Thanks for all the thoughtful and helpful comments on my previous post on blocking statistics. After continued thought and consideration, I have come up with a few points that must be considered when developing a useful blocking statistic (for middle blockers).
- I won’t say it is the most pointless statistic ever, but I will say blocks per set is NOT a useful blocking statistic. Firstly, it is too dependent on other skill areas (for example service aces and errors reduce the number of blocking opportunities). Secondly, a fifth set is only 60% of a set and yet it counts as a whole set. Thirdly, in a single match individual blocker can have vastly different numbers of attempts.
- Any useful blocking statistic must be measured against attempts to block, or number of opponent’s attacks.
- Any useful blocking statistic must be be weighted for different game situations, for example perfect reception, bad reception, transition etc.
Having determined those ‘principles’, I have reached something of an impasse as I have neither the total access to data nor the mathematical skills to really even begin to consider how I might put that into a single number. But I am able to measure some of those things individually and have been working with some of those numbers.
For your interest I have been recording (via Data Volley) which middle blocker is involved in every opponent attack, even if they do not actually attempt to block. Here I am making the assumption that a middle blocker being involved or not involved in a block is an indication of skill (for example footwork, reading) and tactical awareness (choosing when to commit or read). After I have done that I have a whole worksheet of numbers on my middles. The numbers I have found myself most interested in for each individual middle blocker are:
- Opponent’s attack percentage (after reception and transition)
- My team’s (break) point scoring percentage
- My team’s (break) point scoring percentage after perfect and positive reception
- My team’s (break) point scoring percentage after good reception
- My team’s blocking percentage for each middle blocker (the percentage of blocks the team gets when that middle blocker is frontrow)
The results are really interesting, even if I don’t know how meaningful they are. It does seem clear that middles have skills in different areas. For example, my three middles are almost identical in opponent attack percentage, but very different in the break down between reception and transition attack. Further, the difference in break point percentage between the three is small, but when broken down by the quality of reception there are also big differences.
At this point it is all just things to think about…
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