Post by The Bofa on the Sofa on Sept 26, 2009 12:08:45 GMT -5
Hitting percentage is (kills - errors)/total attacks
Does it make sense to subtract the errors? I know you want it seems reasonable to penalize errors, but is that correct?
Actually, the answer is, yeah, that probably pretty close. It might be a little off, but it's probably not too bad. Here's why:
What is implication of hitting pct? Let's consider two hitting lines:
Player A: 6/3/15
Player B: 3/0/15
Both players have hit .200, but the first has done it with more kills and more errors. Which of these contributions is better?
Actually, it depends on what happens in those balls that aren't kills or errors. For example, what happened in those 6 attacks that were dug for player A? If they were all turned into kills for the other team, than that means player A attacks only led to 6 points for the team. Then again, if all of player B's attacks resulted in kills for the other team, than that player's attacks only led to 3 points for the team. Therefore, in that type of scenerio (where a non-terminated attack always leads to a point for the opposition), then 6/3/15 is much better than 3/0/15.
Then again, it's not likely that a dug attack always leads to a point for the other team. We know that the scoring success on serve receive, for example, is only about 70%, and I wouldn't expect the average dug ball to be easier than serve reception. But let's assume that's basically what it is. Assume that non-terminated kills are converted 2/3 of the time. Then which line is better?
For player A, that means that 4 of the 6 non-terminated balls are points for the other team. That means that player A created 8 points for the team, and the opponents had 7.
For player B, 8 of the 12 non-terminated balls were points for the opponents, so player B created 7 points, and the opponents had 8. Again, player A, the one with more kills and more errors, contributed more to winning.
Now, hitting pct suggests that their contributions were the same. What does this imply? In the same sense as above, it means that the opposition converts 50% of the attacks that are not terminated. So half of the 6 for player A are points for the opposition, and half of the 12 for player B are points for the opposition. Thus, both players lead to 9 points.
The question is, what is the real percentage of conversion on non-terminated attacks? As I said above, we shouldn't expect it to be more than say, 70%, the sideout percentage. Moreover, I think it is a fair assessment to think that it should be lower than that. Attacks that get dug might not be terminated, but they can also put the other team off-balance. This could in principle be offset by some easier shots, but then again, free balls are generally not (supposed to be) considered as attacks. I think it is fair to argue that (on average - individuals' milage may vary) the typical non-scoring attack is harder to convert than a serve. On the whole, some may be easier for the opponent, some may be harder, so an estimate of 50%, while probably not exactly right, is also probably not too far from realistic. As such, it would mean that, yes indeed, player A and player B contribute the same, as hitting % says they do.
Now, that is referring to overall pcts, and there will be individuals whose pcts will vary. If, for example, a player's non-terminated attacks are being converted at more than 50% by the opponents, it means they should probably get more aggressive. Similarly, if non-terminated attacks are converted at less than 50%, the player can get more conservative.
(if anyone has the real numbers for conversion, that would be usefull and would affect the analysis)
Does it make sense to subtract the errors? I know you want it seems reasonable to penalize errors, but is that correct?
Actually, the answer is, yeah, that probably pretty close. It might be a little off, but it's probably not too bad. Here's why:
What is implication of hitting pct? Let's consider two hitting lines:
Player A: 6/3/15
Player B: 3/0/15
Both players have hit .200, but the first has done it with more kills and more errors. Which of these contributions is better?
Actually, it depends on what happens in those balls that aren't kills or errors. For example, what happened in those 6 attacks that were dug for player A? If they were all turned into kills for the other team, than that means player A attacks only led to 6 points for the team. Then again, if all of player B's attacks resulted in kills for the other team, than that player's attacks only led to 3 points for the team. Therefore, in that type of scenerio (where a non-terminated attack always leads to a point for the opposition), then 6/3/15 is much better than 3/0/15.
Then again, it's not likely that a dug attack always leads to a point for the other team. We know that the scoring success on serve receive, for example, is only about 70%, and I wouldn't expect the average dug ball to be easier than serve reception. But let's assume that's basically what it is. Assume that non-terminated kills are converted 2/3 of the time. Then which line is better?
For player A, that means that 4 of the 6 non-terminated balls are points for the other team. That means that player A created 8 points for the team, and the opponents had 7.
For player B, 8 of the 12 non-terminated balls were points for the opponents, so player B created 7 points, and the opponents had 8. Again, player A, the one with more kills and more errors, contributed more to winning.
Now, hitting pct suggests that their contributions were the same. What does this imply? In the same sense as above, it means that the opposition converts 50% of the attacks that are not terminated. So half of the 6 for player A are points for the opposition, and half of the 12 for player B are points for the opposition. Thus, both players lead to 9 points.
The question is, what is the real percentage of conversion on non-terminated attacks? As I said above, we shouldn't expect it to be more than say, 70%, the sideout percentage. Moreover, I think it is a fair assessment to think that it should be lower than that. Attacks that get dug might not be terminated, but they can also put the other team off-balance. This could in principle be offset by some easier shots, but then again, free balls are generally not (supposed to be) considered as attacks. I think it is fair to argue that (on average - individuals' milage may vary) the typical non-scoring attack is harder to convert than a serve. On the whole, some may be easier for the opponent, some may be harder, so an estimate of 50%, while probably not exactly right, is also probably not too far from realistic. As such, it would mean that, yes indeed, player A and player B contribute the same, as hitting % says they do.
Now, that is referring to overall pcts, and there will be individuals whose pcts will vary. If, for example, a player's non-terminated attacks are being converted at more than 50% by the opponents, it means they should probably get more aggressive. Similarly, if non-terminated attacks are converted at less than 50%, the player can get more conservative.
(if anyone has the real numbers for conversion, that would be usefull and would affect the analysis)
