ATP Injury analysis

In previous articles we have looked at how well the new upgraded ATP model has done against certain probabilties and overlays. This analysis can be found linked on the right hand side of this page: http://www.sportpunter.com/sports/tennis/

However another interesting piece of information is how well the model goes based on our injury ratings. Sportpunter’s tennis model has four injury ratings and they are as follows

SurfaceNoPlay – Player has not played on this particular surface in last 2 months

LowPlay – Player has not won a match (or played) in last 2 months

Retire – Player has recorded at least 2 retirements or withdrawals in last 2 months

LossRetire – Player has not won a match since last retirement or withdrawal

Based on suggested bets from back to 2005, we can see how the model goes when betting on games where one of the above scenarios occur.

Shown below are the results of the ATP model for betting on players with the above scanerios (1), against a player with the above scenarios (-1) or when both players have, or do not have, the injury conditions.

The findings are quite substantial. Betting on a player who has not played on the particular surface recently resulted in an 8.1% loss from 310 bets, whilst a 9% ROI gain was made when the suggested bet was the other way around.

Similarly, when betting on a player who has not won or played a match recently, a 16.8% ROI loss was made, as compared to a 9% ROI gain the other way around.

There was little difference in the variables Retire and LossRetire for both betting for or against the injured player.

So what does this mean? Well, all these variables are in the model, and hence the model has accurately calculated the value of each one. However there still seems to be a bias there.

My conclusion is that the odds are biased in that they do not much enough for when a player has not played for a certain amount of time, or are “first up” in the last 2 months on a particular surface.

SurfaceNoPlay	#Bets	#Won	%Won	$Bet	$Profit	%ROI
1	310	134	43.2%	$58,571.28	-$4,720.81	-8.1%
0	9014	3791	42.1%	$1,387,954.09	$73,440.46	5.3%
-1	544	252	46.3%	$119,623.03	$10,773.26	9.0%
TOTAL	9868	4177	42.3%	$1,566,148.40	$79,492.91	5.1%
LowPlay	#Bets	#Won	%Won	$Bet	$Profit	%ROI
1	205	69	33.7%	$37,172.96	-$6,232.67	-16.8%
0	9243	3849	41.6%	$1,408,208.11	$74,917.63	5.3%
-1	420	259	61.7%	$120,767.33	$10,807.95	8.9%
TOTAL	9868	4177	42.3%	$1,566,148.40	$79,492.91	5.1%
Retire	#Bets	#Won	%Won	$Bet	$Profit	%ROI
1	92	29	31.5%	$15,231.53	-$3,054.57	-20.1%
0	9600	4069	42.4%	$1,514,310.56	$85,275.43	5.6%
-1	176	79	44.9%	$36,606.30	-$2,727.95	-7.5%
TOTAL	9868	4177	42.3%	$1,566,148.40	$79,492.91	5.1%
LossRetire	#Bets	#Won	%Won	$Bet	$Profit	%ROI
1	420	183	43.6%	$78,125.39	$1,166.83	1.5%
0	9043	3820	42.2%	$1,416,602.14	$76,547.49	5.4%
-1	405	174	43.0%	$71,420.86	$1,778.58	2.5%
TOTAL	9868	4177	42.3%	$1,566,148.40	$79,492.91	5.1%