Monday, December 21, 2015

Volleyball Basics - Rotations, Side Out Percentage

In my opinion, one of the most useful volleyball stats for coaches is side out percentage (SO%). SO% is simple. It is points scored on serve receive divided by total attempts. It is a simple stat to record. One coach or player simply records a 1 for point on serve receive and a 0 for a point lost on serve receive. After the match the total number of 1's and 0's is recorded, the 1's are divided by the total of both numbers. That's the SO%. The same can easily be done for the opponent to get your team's scoring percentage, or their SO%.

In the recent NCAA women's tournament championship match, the AVCA twitter feed featured some stats from the match collected by Data Volley. One that immediately stood out to me was this one:
Something I heard many years ago about SO% is that two teams with the same SO%, let's say 50%, played each other 30 times, each team would usually end up with 15 wins. If one team improves to 51% and holds the other team to 49% and they play 30 times, the team with the 51% improves to 20 wins. That's a big change in the outcome of a season from a small change in team performance. I have run computer simulations of these scenarios and the win numbers are supported by the simulation data. The simulation numbers were a little off, but they're close enough. Side out percentage is a simple to measure stat that gives actual meaningful information.

A simple way to get even more information is to record SO% by rotation. There are six rotations and each one will have its own SO%. This information will give coaches a quick idea of where the team does well and where it struggles. Two simple ways this information can help in coaching is to give information about where the team can improve and to help decide about which rotation is the best one to start each set.

One way to use SO% to improve is to play games with the team in a rotation where they struggle and try to score some goal number of points out of ten tries. If your team has a 60% overall SO%, your team might have a goal of 6 points out of 10 attempts for those problem rotations.

Side out percentage should be taken into consideration when deciding on which rotation to start sets. The majority of teams I have coached against have started in rotation 1 with the setter as the first server. If that rotation or one soon after has a bad SO% it could cost the team over the season. Running computer simulations of matches starting at different rotations using real by rotation SO%, my teams could realistically win another match or two by starting in the right rotation. Matches rarely have teams play each rotation an equal number of times. Starting with your best rotations make it more likely to give those better rotations more opportunities. It isn't a huge difference, but over many matches it can add up. Against an opponent that is otherwise very close to your team this could make the difference. Another consideration is that any time your SO% is above 50%, it is more advantageous to start matches in serve receive than with the serve. Possibly the only place I would still want to serve first is if my best server is also at the beginning of our best serve receive rotations.

Side out percentage is one of the easiest stats to collect, even with pen and paper, and it is very useful for coaches. I recommend using it to make coaching decisions for practice design and competition choices. Small improvements in side out percentage can make a huge difference in your season wins and losses. Making the right decisions as far as something as simple as which rotation you start each set could mean another win or two.



Volleyball Basics are intended to present some of the fundamental volleyball knowledge that everyone serious about the sport should know.

Wednesday, December 16, 2015

Stephen Curry's Unusual Basketball Training

A few weeks back I saw a video talking about Stephen Curry and his work ethic displayed at a young age. I think it really captures what it takes to become an elite level athlete in a sport. I was hesitant to write about it because of the physical demands of volleyball and how they differ from those of basketball. Overuse is a serious concern in volleyball. Too much hitting can lead to shoulder injury. Too much jumping can lead to lower extremity injury. Still the sentiment remains. The best players are likely the ones who train on their own outside of scheduled practice time, even if it is just showing up 15 minutes early, or staying after a few minutes.

Extra practice time and over-training aside, getting more reps is necessary for improving at a skill. Of course, the more specific the practice the better. With that in mind, I saw this video and article. It was interesting to me, but most of it is not applicable to volleyball. Basketball is a much more random sport than volleyball with a lot more contact. Dribbling in particular doesn't really have a volleyball equivalent. Dribbling a basketball is something that the best players do without looking at what they are doing, and being able to split their attention between the skill and court conditions around them is valuable. the dribbling drills make sense. I don't know how valuable the other stuff with the goggles and tennis balls is, but it is an interesting hypothesis. He is getting a lot of reps dribbling, but I don't know how the lack of specificity is helping or not.

The thing that I think is important to take away from it is the part about the practice reps he gets from longer than conventional three point range. The article mentions the trainer thinking Curry will eventually start to incorporate half court shots into his regular game instead of just end of game buzzer beaters. I'll leave the discussion of whether or not that makes basketball sense to basketball people. I think the lesson to learn is that it might be a good idea to invest practice time and reps to unusual situations that sometimes arise in matches. Maybe put your team on serve receive down 21-24 and see if they can rally and win the set. Maybe 21-24 is an unrealistic starting point, but put them in a position where they need to make a comeback to win. Familiarize your team with the situations that arise in matches that often cost teams wins. Make the situation familiar, and the solution will also be familiar. They do it all the time in practice.

And Ivan Zaytsev's serving run was ridiculous.


Tuesday, December 15, 2015

Volleyball Basics - Overlap in Rotations

Figure 1 - Overview of overlap
One of the key pieces of information needed to understand rotations and how to alter them is overlap. When the ball is served, at the point of contact each player needs to be in their position as indicated by the serve order. The player serving in this rotation is in zone 1 in the back right. The next server is in 2 in the front right, and so on as can be seen in figure 1. This is just a representation of the zones of the court. The arrows indicate how the players need to be positioned in relation to each other. 1 needs to be behind 2 and to the right of 6. 3 needs to be in front of 6, to the right of 4, and to the left of 2. These restrictions only apply to the players the arrows point to. There is no restrictions on where players are positioned in relation to players diagonal from them.


Figure 2 - Example serve receive rotation
Figure 2 illustrates a legal serve receive formation. 5, 6, and 1 are in the back row and correspond with the positions illustrated in figure 1. The player in zone 1 has just served (service order 1) and the team is now in serve receive. 2, 3, and 4 are in the front row. 2 will be the next server upon side out. In this situation 4, 5, and 1 are primary passers and will receive the majority of serves.









Figure 3 - Overlap arrows for the player 6th in service order
Figure 3 shows the arrows that apply to the player (in black) 6th in service order. The players in red are the ones 6 needs to be concerned with in this situation. 6 needs to be behind 3, to the right of 5, and to the left of 1. The players in grey are diagonal from 6 and have no bearing on 6's position on the court. This is why front row players 2 and 4 can be behind 6 even though they are front row players.







Figure 4 - Overlap arrows for the player 4th in service order
Figure 4 shows the arrows that apply to the player (again in black) 4th in service order. In this case the player only has two players to be concerned with, 3 and 5 in red. Players 1, 2, and 6 in grey are diagonal from 4 and have no bearing on 4's position on the court. 4 only needs to be in front of 5 and to the left of 3. This kind of formation is common in 3 passer systems. 4 doesn't have to be very far in front of 5 to be legal. Sometimes this can be seen with 4's toes only slightly closer than 5's toes, and 5's heels are only slightly closer to the service line.



Keys to remember:
1. Service order with current server when serving and most recent server is number 1 after losing serve.
2. Players' position on the court in relation to each other is governed by service order as illustrated in figure 1.
3. Each player needs to maintain the forward/back and left/right positioning based on their arrows shown in figure 1.
4. The forward/back and left/right positioning can be very small.

Use these key points when using and adjusting serve receive formations.


See also:
Zones of the Court
Introduction to Rotations

Volleyball Basics are intended to present some of the fundamental volleyball knowledge that everyone serious about the sport should know.

Sunday, December 13, 2015

Volleyball Basics - Introduction to Rotations

One of the fundamental aspects of organized team play in volleyball is the use of rotations. Rotations are designed to ensure a front row/back row balance for positions and their roles in the offense and defense. They are also used to place players in a position on the court so they can receive serve, if that is one of their responsibilities, and move into the areas on the court where they will be set. Serve and serve receive rotations place players so they can perform their primary responsibilities with a minimum of movement.

Front row/back row balance is accomplished by placing the outside hitters opposite each other in the service rotation, middle blockers are opposite each other, and the setter is opposite the, well, opposite. To differentiate outsides and middles, they are labeled outside hitter 1 and middle blocker 1 for those either side of the setter in service order, and outside hitter 2 and middle blocker 2 next to the opposite in service order.


Base defensive positions with setter in back row.
Rotations are numbered by serving order, the setter is first. For rotation 1, the setter is in zone 1, outside hitter 1 is next in serving order in zone 2, middle blocker 2 in zone 3, the opposite in 4, outside hitter 2 in 5, and middle blocker 1 in 6.

In rotations with the setter on the back row (rotations 1-3), the base defensive positions place the front row outside in 4, the front row middle in 3, and the opposite in 2. The setter is in 1, the back row outside is in 6, and the libero (or the back row middle when serving) is in 5. In rotations with the setter in the front row, the setter and opposite trade places. This places the players where they need to be when transitioning to and from offense with as little unnecessary movement as possible.

See also:
Zones of the Court

Volleyball Basics are intended to present some of the fundamental volleyball knowledge that everyone serious about the sport should know.

Saturday, December 12, 2015

13 Is A Magic Number

Tonight's NCAA regional quarterfinal between Kansas and USC had me thinking about the idea of 13 kills being a sort of magic number (see here and here). Get that and you are going to have a good chance to win the set. Similarly, hold the other team to 10 kills, or be +3 kills when comparing your kills per set to their kills per set. So how did the teams do?

Kansas vs USC
Kansas took the first two sets, 11-9 in kills for a +2, and 12-10 for another +2. USC took the next two, 18-11 (+7) and 14-13 (+1). The final set went to Kansas, 10-9 (+1). 13 kills per set scales down to 8 kills per set on a 15 point set.

Texas vs Florida
Florida took sets 1 and 4, 15-13 (+2) and 15-12 (+3). Texas took sets 2 and 3, 16-17 (-1) and 15-11 (+4). The final set went to Texas 11-9 (+2).

Minnesota vs Hawaii
Minnesota took sets 1, 2, and 4, 16-12 (+4), 12-9 (+3), and 20-16 (+4). Hawaii won their set 22-15 (+7).

Nebraska vs Washington
Nebraska took sets 1, 3, and 4, 11-10 (+1), 19-12 (+7), and 20-13 (+7). Washington took their set 15-12 (+3).

On 18 total sets played this round, each set winner outscored the other team in kills with one exception. Six total sets had the winning team with less than 13 kills, but two of those were fifth sets. Ten sets were won with 3 or more kills separating the teams. Losing teams managed to collect more than 10 kills 13 times. It's a small sample, but scoring 13 or more kills per set resulted in a win 75% of the time when removing fifth sets. Having at least 3 more kills than the other team resulted in a win 55.6% of the time. Achieving both standards resulted in a win every time. After removing the fifth sets, there are only the sets where a team was held to 10 or fewer kills. Each of those three sets were lost by those teams held to no more than 10 kills. That will probably be the toughest standard to achieve. This round of the tournament seems to support the standard of 13 kills per set, holding the other team to no more than 10, and getting at least 3 more kills than the other team.

Tuesday, December 8, 2015

Sitting Volleyball And Skill Transfer

John Kessel's blog post from September 22, 2014, Top Ten Reasons for a Club to do Sitting Volleybal Training,  showed up in my social media feed today. If you're unfamiliar, sitting volleyball is a variation of volleyball for players with physical impairments. Unlike other sports variants, sitting volleyball is not played from a wheel chair. There are videos of it on YouTube worth watching.

In the blog post, Kessel gives these reasons to break out sitting volleyball for your team:
1. Fun
2. A break from jumping
3. Empathy/awareness for them for disabled/Paralympic sport
4. Get them to be talent scouts for any possible future Paralympians
5. Gets you to use your overhead skills well
6. A way to keep lower limb injury teammates bonded/playing with the team at times
7. Practice arm movement for blocking but no need for a "box"
8. Speed up reading of opponent's upper body - net at 1.15m and court half the length of regular makes for FAST ball net crossing/arrival
9. A great leveler for tall to short - and parents can play too
10. Fun

I can't speak to 1 and 10, but I can't find fault with it. I imagine it would be a lot of fun. 3 is valuable for us as human beings. 4 just seems unlikely to be a reality. I think these are reasons to play sitting volleyball that are outside of immediate concerns and goals of the players and coaches.

2 and 6 are interesting. Overuse injuries are a real concern for coaches and players. Too much jumping can lead to patellar tendonitis and every time you land is another chance for a rolled ankle or worse. This isn't unique to volleyball, but leg and shoulder overuse injuries are a significant concern for front row players. These are closer to immediate concerns and goals of players and coaches. Similar to 2 and 6, using it as a leveler for short, tall, and even parents (number 9 on the list) would be a fun way to include everyone in the sport.

That leaves 5, 7, and 8 as reasons to play sitting volleyball in our practices that more closely approach addressing concerns and goals of players and coaches. It would get you to rely on overhead skills more, arm work would be much more important at the net in blocking (and hitting), and you would need to be faster reading your opponent's upper body. These are all worthwhile and desirable outcomes. The problem is do they transfer?

Skill transfer is greatest when the practice is specific to performance in competition. Basketball players commonly can shoot 10 free throws in a row, but hitting that one or two in a close game situation are elusive. How many times does a basketball player need to hit 10 free throws in a row? How many times in a game is that player going to shoot free throws in such a favorable environment (thinking mainly about the pressure of the situation here and not crowd noise or other external factors)? Our athletes need to develop the basic mechanics of the skill (lots of reps) and also they need to develop the ability to execute that skill in competition. Overhead skills are going to be developed, but the demands of sitting volleyball will best train those abilities in ways that will make little impact on the traditional game. A typical overhead pass in sitting volleyball will probably not get the ball high enough to let a standing teammate then use an overhead pass or hit a down ball. Any improvement in arm movement in blocking will still not address any footwork or eyework at the net. The visual cues the player reads in sitting volleyball will be only a small portion of the overall skill to read hitters in traditional volleyball, if they are the same at all. In some players at least, I'm sure the visual cues a hitter displays in sitting volleyball will be different. Sitting volleyball is going to be fun, it is going to be inclusive, and it will be a nice break from standard training, but I think it is a disservice to think of it as an effective training method.

Should you use sitting volleyball with your team? That is entirely up to you. It probably will be fun and appropriately represent the 7 of 10 reasons in the list that are independent of skill development. If you are doing it for those 3 reasons related to skills, you are probably better served doing something else much more specific to the game you will be playing in competitions. Those three reasons are really what bothers me about suggestions like this, especially when it comes from a respected coach and teacher. This kind of approach is why a lot of ineffective training methods persist. It's why a lot of teams do a lot of silly drills and then under-perform in competitions. It is hard to elevate the game when these ideas stick around. Play sitting volleyball to have fun. Just don't expect your team to get better because of it.

Saturday, December 5, 2015

Does A Coach Have To Be A Great Player

There is a common belief that a great player will make a great coach, but is it true? I have long thought that it is not true. Going back to statistics and learning about probabiliy distribution, each skill or trait should have a distribution where the elite skill is only present in a small percentage of the population. A specific combination of skills and traits will therefore be even less likely. Simplified, if elite passing is present in 2% of the population, elite passing and elite hitting will be present in 2% of 2% (or 0.04%) of the population. The greater number of skills, the less likely that combination is present in the population.

Then comes coaching. I think it is common for people to think that playing ability equates to coaching ability. Coaching is a completely different animal. Some players are good at a skill, but they might not know how to describe what they do, or how they do it. They might not be able to teach how to do it. What they do might be instinctive. I remember hearing a sound clip of Brett Favre thanking Ty Detmer in an interview or press conference for teaching him what the Cover 2 defense was. Favre was a future Hall of Fame quarterback, and Ty Detmer was his backup who only played in 7 games during their time as teammates.

Coaching is a complex stew of skills. Knowing the fundamental skills of your sport is important, but being an elite player and having the skills to be an elite coach is going to be ridiculously unlikely. While not approached from this theoretical base, this article about Barry Bonds on fivethirtyeight.com demonstrates this idea with numbers. It's a nice treatment on the subject using baseball's massive collection of stats. It takes advanced playing stats of Baseball hitting coaches who played major league baseball and an advanced stats measure of team hitting stats versus their expected stats.

As theory predicts, there is no correlation between playing ability and coaching ability. In fact the plot looks like just another way to visualize the probability distribution. There are a lot of hitting coaches who were poor players relative to the rest of the population evaluated. There are fewer hitting coaches who were great players. Average improvement over expectations for team performance is pretty close to zero. The line on the graph indicating that average actually drops slightly below zero improvement as the coach's playing ability increases. This suggests that hiring a stud hitter as a hitting coach will most likely result in no improvement over the previous hitting coach. It almost suggests that hiring the stud hitter will actually result in a decline. The best hitting coach was a pretty poor hitter compared to the rest of the sample.

The take home message is that coaches shouldn't worry about how good of a player he or she was. It is more important to learn and improve in those skills specific to teaching the game, and improving your knowledge base.

Thursday, December 3, 2015

Micah Christenson's CEV Top Play


Top Play: Micah Christenson
By the beard of Zeus, what was that!? LUBE Volley's Micah Christenson delivers a top play, that you have never seen before! Watch today's #CEVChampionsLeagueM matches LIVE on LAOLA1.tv -> bit.ly/CEV_LiveCEV - Confédération Européenne de Volleyball #Volleyball
Posted by LAOLA1.tv on Thursday, December 3, 2015
I just saw this video clip floating around today on social media. Micah Christenson makes a great play for his Italian team. The pass on serve receive was bad, and he had no chance to set. What I really like about what he does is that as soon as the ball goes over the net, he identifies the hitter and is watching the hitter (Ball-Setter-Ball-Hitter). The end result is a seriously broken play is converted to a point.