MLB Betting: Results of Predicting Win Totals Using Sabermetrics

Mark Lathrop

Monday, October 19, 2015 12:12 PM GMT

Monday, Oct. 19, 2015 12:12 PM GMT

Earlier in 2015, I proposed a system of projecting wins by using two sabermetrics projection systems, fWAR & Steamer, and applying them to the MLB futures for win totals. The results are in.

To recap, to calculate these projected win totals I used a regression based on the projected total WAR for each roster. WAR stands for Wins Above Replacement, or how valuable a player is related to a replacement level player. The regression formula to calculate the win total was based off of the statistical work of sabermetrics expert, Glenn DuPaul.

First let’s will review the results using the Steamer WAR projections. This projection system was more bullish than the fWAR system, as it projected that 21 teams would go over the O/U total listed at Bovada. That left just 9 teams with a projected record that warranted a bet on the Under season win total. However, of those 9 teams suggested to go under the win total 8 of them in fact did. 8-1 is a pretty strong result and the only team that bucked the trend is the New York Mets. The Over suggestions were 11-10, not a disaster, and overall the system was 19-11 in choosing the right direction for the season MLB picks win total.

Here are the full results using the Steamer WAR projections:

 

Steamer Projected Win Totals vs Bovada O/U Wins

 

TEAM Steamer Projected Wins O/U (Bovada) Diff. Lean Actual Wins Result
COL 82.17 71.5 10.67 Over 68 Loss
BOS 95.17 86.5 8.66 Over 78 Loss
MIN 80.23 72.5 7.73 Over 83 Win
OAK 88.08 81.5 6.584 Over 68 Loss
KC 85.47 80.5 4.97 Over 95 Win
TB 83.33 78.5 4.83 Over 80 Win
SEA 90.61 86.5 4.106 Over 76 Loss
HOU 79.06 75.5 3.563 Over 86 Win
NYY 84.98 81.5 3.48 Over 87 Win
CLE 87.60 84.5 3.10 Over 81 Loss
ARI 74.50 71.5 3.00 Over 79 Win
DET 86.92 84.5 2.42 Over 74 Loss
TEX 79.74 77.5 2.242 Over 88 Win
CHC 84.59 82.5 2.09 Over 97 Win
MIL 80.52 78.5 2.02 Over 68 Loss
BAL 84.01 82.5 1.51 Over 81 Loss
CIN 78.87 77.5 1.37 Over 64 Loss
TOR 84.79 83.5 1.29 Over 93 Win
STL 89.44 88.5 0.94 Over 100 Win
PIT 84.98 84.5 0.48 Over 98 Win
WAS 93.71 93.5 0.21 Over 83 Loss
CWS 80.81 81.5 -0.69 Under 76 Win
ATL 72.66 73.5 -0.84 Under 67 Win
PHI 67.04 68.5 -1.47 Under 63 Win
MIA 80.91 82.5 -1.59 Under 71 Win
LAD 90.51 92.5 -1.99 Under 92 Win
LAA 86.44 88.5 -2.065 Under 85 Win
SF 82.17 84.5 -2.33 Under 84 Win
NYM 76.25 81.5 -5.25 Under 90 Loss
SD 75.77 84.5 -8.74 Under 74 Win

 

The fWAR projections from Fangraphs had more of a lean towards picking the under, but still was a system that was successful with an overall 20-10 record. Again, the Under leans had the best results at 13-5, against just 7-5 for the Over leans. The reasons for this is likely due to the public betting markets allowing the books the ability to inflate O/U win totals on popular teams. True talent evaluation and mathematics will throw that bias out.

Here are the full results using the fWAR projections:

 

fWAR Projected Win Totals vs Bovada O/U Wins

TEAM fWAR Projected Wins O/U (Bovada) Diff. Lean Wins Result
ARI 75 71.5 3.5 Over 79 Win
COL 75 71.5 3.5 Over 68 Loss
TB 82 78.5 3.5 Over 80 Win
HOU 78 75.5 2.5 Over 86 Win
CHC 84 82.5 1.5 Over 97 Win
MIN 74 72.5 1.5 Over 83 Win
OAK 83 81.5 1.5 Over 68 Loss
MIL 79 78.5 0.5 Over 68 Loss
NYY 82 81.5 0.5 Over 87 Win
PHI 69 68.5 0.5 Over 63 Loss
PIT 85 84.5 0.5 Over 98 Win
SEA 87 86.5 0.5 Over 76 Loss
ATL 73 73.5 -0.5 Under 67 Win
BOS 86 86.5 -0.5 Under 78 Win
CIN 77 77.5 -0.5 Under 64 Win
CLE 84 84.5 -0.5 Under 81 Win
DET 84 84.5 -0.5 Under 74 Win
NYM 81 81.5 -0.5 Under 90 Loss
TOR 83 83.5 -0.5 Under 93 Loss
WAS 93 93.5 -0.5 Under 83 Win
KC 79 80.5 -1.5 Under 95 Loss
LAD 91 92.5 -1.5 Under 92 Win
MIA 81 82.5 -1.5 Under 71 Win
SD 83 84.5 -1.5 Under 74 Win
STL 87 88.5 -1.5 Under 100 Loss
LAA 86 88.5 -2.5 Under 85 Win
SF 82 84.5 -2.5 Under 84 Win
BAL 79 82.5 -3.5 Under 81 Win
TEX 74 77.5 -3.5 Under 88 Loss
CWS 77 81.5 -4.5 Under 76 Win

 

I’ll definitely be repeating this next year as I made quite a bit of coin wagering on MLB futures this year. Next year I’ll also likely hammer the Under projections a bit more, as they appear to be have the strongest correlation in the model. 

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