I've been shooting air rifle benchrest matches at the excellent Open Grove Oxnard range for almost 4 years now. There are 14 benches, and some shooters say that some of the benches are better (score higher) than others - based on where each position is in relation to buildings and trees that could affect the wind.
From match to match I try to shoot from different benches, and I shoot the same rifle and power class every match, and have saved most of the match cards. I decided to check my score data to evaluate whether there is an advantage or disadvantage as a function of bench position.
There were 116 cards (!), shot from benches 2, 3, 4, 5, 6, 7, 8, 11, 12, 13 (None were shot from #1,9,10,14). Here are the mean scores by bench number, and number of cards shot at each bench:
Bench Cards Mean
02 18 247.50
03 11 248.00
04 06 246.00
05 12 247.17
06 06 248.00
07 12 245.33
08 06 247.17
11 03 244.67
12 23 246.78
13 19 247.58
The highest mean scores were bench 6 (near the middle) and bench 3, followed closely by benches 13 and 2.
Perhaps scores differ by general area of the range: towards the left side, middle, and right side? To check this, scores were pooled from left benches (#1,2,3,4), middle (5,6,7,8,910), and right benches (11,12,13,14). Here are the means for these areas:
Area Cards Mean
Lt 35 247.40
M 36 246.69
Rt 45 246.98
The highest mean score was for the left side benches. However it was only 0.71 point higher than the middle benches, and 0.42 higher than right side benches.
There was enough data to run tests of statistical significance (in this case t-test, which presumes data is distributed normally and gives the probability that differences could have happened by chance alone). Testing the left bench mean against the middle and the right showed no statistical significance (ie the differences were likely to have occurred by chance alone).
Based on this analysis it is hard to conclude there are better benches over many matches and conditions. (It doesn't rule out advantages for a given condition, however)
From match to match I try to shoot from different benches, and I shoot the same rifle and power class every match, and have saved most of the match cards. I decided to check my score data to evaluate whether there is an advantage or disadvantage as a function of bench position.
There were 116 cards (!), shot from benches 2, 3, 4, 5, 6, 7, 8, 11, 12, 13 (None were shot from #1,9,10,14). Here are the mean scores by bench number, and number of cards shot at each bench:
Bench Cards Mean
02 18 247.50
03 11 248.00
04 06 246.00
05 12 247.17
06 06 248.00
07 12 245.33
08 06 247.17
11 03 244.67
12 23 246.78
13 19 247.58
The highest mean scores were bench 6 (near the middle) and bench 3, followed closely by benches 13 and 2.
Perhaps scores differ by general area of the range: towards the left side, middle, and right side? To check this, scores were pooled from left benches (#1,2,3,4), middle (5,6,7,8,910), and right benches (11,12,13,14). Here are the means for these areas:
Area Cards Mean
Lt 35 247.40
M 36 246.69
Rt 45 246.98
The highest mean score was for the left side benches. However it was only 0.71 point higher than the middle benches, and 0.42 higher than right side benches.
There was enough data to run tests of statistical significance (in this case t-test, which presumes data is distributed normally and gives the probability that differences could have happened by chance alone). Testing the left bench mean against the middle and the right showed no statistical significance (ie the differences were likely to have occurred by chance alone).
Based on this analysis it is hard to conclude there are better benches over many matches and conditions. (It doesn't rule out advantages for a given condition, however)