from Amazon
Thursday, June 10, 2010
Regression equation for types of pitches versus platoon ratio
I created a data file containing the following variables and ran a multiple regression (using Excel) on it:
All pitchers in 2006-2009 who faced at least 300 RH batters (excluding IBB and SH).
All pitch type percentages were taken from FanGraphs. Pitch type percentages do not add to 100% for each pitcher because I did not include in the data file cutters and knuckleballs - only fastballs (FB), sliders (SL), curve-balls (CB), change-ups (CH), and splitters (SF).
I computed each pitcher’s platoon OPS ratio for each year. Platoon OPS ratio is simply opposite hand batters’ OPS divided by same-hand batters’ OPS, where OPS includes HPB, SF, but not IBB.
So each line in the data file was for one pitcher and one year (for example, Halliday, 2006), and included:
Variable X1: FB %
Variable X2: SL %
Variable X3: CB %
Variable X4: CH %
Variable X5: SF %
Variable Y: Platoon OPS ratio
N was 424 (424 lines of data, each line being a pitcher and year).
Dave Allen (I think - please correct me if that is wrong) in one of the THT annuals and on the THT site computed the following platoon differentials (runs per 100 pitches I imagine) based on the run values of each of the types of pitches. These are for RHP only and are “adjusted” (you’ll have to read the article to know what that means - I forgot). I think he used pitch f/x data, but I am also not sure about that.
pitch platoon
Slurve 1.12
Sinker 1.08
Heater 0.80
Slider 0.57
Rider 0.56
Cutter 0.41
Jumping fastball 0.27
Rising fastball 0.21
Power change 0.01
Tight curve -0.13
Roundhouse curve -0.69
Straight change -0.77
Anyway, just using the 5 pitch categories from FanGraphs that I mentioned above, here is the regression equation I came up with. Please tell me whether it looks right or not.
RHP (facing > 299 RHB in each pitcher season)
1.004 + .139 * FB + .224 * SL - .246 * CB - .008 * CH - .211 * SF
LHP (facing > 299 RHB in each pitcher season)
1.049 + .349 * FB + .119 * SL - .414 * CB - .582 * CH + .679 * SF
As a sanity check, if we plug in the average values for all RH and LH pitchers (who faced at least 100 RH batters in each year), we get the following predicted platoon ratios for all of these pitchers combined:
RHP 1.098
LHP 1.160
The average percentages from Fangraphs for 2006-2009, for all RH and LH pitchers who faced at least 100 RHB in a year was:
RHP
FB: 61.0% SL: 15.5 CB: 8.7 CH: 9.1 SF: 1.6
LHP
FB: 59.4% SL: 14.1 CB: 8.8 CH: 13.6 SF: .3
Recent comments
Older comments
Page 1 of 344 pages 1 2 3 > Last »Complete Archive – By Category
Complete Archive – By Date