Two months ago, I made a runs-scored and runs-allowed model in order to predict the probability that the Braves would win both the runs scored title (which they did, easily) and the runs allowed title (which they didn’t, easily.) Both of those results were pretty well predicted by the models, although to be fair almost any sensible model would probably have given a similar result.

I said at the time that once I had that model, I could do other things as well. One of them is predicting the 2023 playoffs. So here goes.

The Model, Modified

I’ve changed the model a bit since then. In particular, I’ve added the ERA of the starting pitcher for the opposing team in the runs-scored model and the ERA of the team’s own pitcher in the runs-allowed model. That’s great news for the accuracy of the model, but bad news for using the model for prediction purposes because we don’t know the identity of the pitchers for anything but the first round, and even there there’s uncertainty.

There are some good and not-so-good ways around this problem: (a) you can use with the model without ERA; (b) you can substitute some sort of average starter ERA; (c) you can guess matchups. The problem with (b) is that the guys who start in the playoffs are considerably better than your average starter. The problem with (c) is that you’re guessing.

I’m going to go with (a) for now, but once I know who the Braves are playing and I have a good sense of the matchups, I might switch over for the Division Series.

All the Numbers

Wild Card Round

TOR vs. MIN:TOR:0.51MIN:0.49
TEX vs. TBR:TEX:0.44TBR:0.56
ARI vs. MIL:ARI:0.43MIL:0.57
PHI vs. MIA:PHI:0.58MIA:0.42

League Division Series Round

HOU vs. TOR:HOU:0.51TOR:0.49
HOU vs. MIN:HOU:0.52MIN:0.48
Overall —HOU: 0.52TOR: 0.25MIN:0.24
BAL vs. TEX:BAL:0.55TEX:0.45
BAL vs. TBR:BAL:0.48TBR:0.52
Overall –-BAL: 0.51TEX: 0.20TBR:0.29
LAD vs. ARI:LAD:0.68ARI:0.32
LAD vs. MIL:LAD:0.60MIL:0.40
Overall –-LAD: 0.63ARI: 0.14MIL:0.23
ATL vs. PHI:ATL:0.64PHI:0.36
ATL vs. MIA:ATL:0.72MIA:0.28
Overall –-ATL: 0.67PHI: 0.21MIA:0.12

League Championship Series Round

vs.ARI: 0.74AggProb: 0.07
vs.MIL: 0.65AggProb: 0.10
vs.LAD: 0.54AggProb: 0.23
vs.PHI: 0.62AggProb: 0.08
vs.MIA: 0.72AggProb: 0.05
vs.ATL: 0.46AggProb: 0.20
vs.ARI: 0.59AggProb: 0.02
vs.MIL: 0.49AggProb: 0.02
vs.LAD: 0.38AggProb: 0.05
vs.TEX: 0.46AggProb: 0.02
vs.TBR: 0.38AggProb: 0.03
vs.BAL: 0.41AggProb: 0.05
vs.TEX: 0.48AggProb: 0.05
vs.TBR: 0.40AggProb: 0.06
vs.BAL: 0.42AggProb: 0.11
vs.TEX: 0.45AggProb: 0.02
vs.TBR: 0.38AggProb: 0.03
vs.BAL: 0.40AggProb: 0.05
vs.TOR: 0.62AggProb: 0.04
vs.MIN: 0.62AggProb: 0.04
vs.HOU: 0.60AggProb: 0.09
vs.TOR: 0.54AggProb: 0.03
vs.MIN: 0.55AggProb: 0.03
vs.HOU: 0.52AggProb: 0.05
vs.TOR: 0.59AggProb: 0.07
vs.MIN: 0.60AggProb: 0.07
vs.HOU: 0.58AggProb: 0.15
vs.PHI: 0.41AggProb: 0.01
vs.MIA: 0.52AggProb: 0.01
vs.ATL: 0.26AggProb: 0.02
vs.PHI: 0.51AggProb: 0.02
vs.MIA: 0.62AggProb: 0.02
vs.ATL: 0.35AggProb: 0.05
vs.ARI: 0.48AggProb: 0.01
vs.MIL: 0.38AggProb: 0.01
vs.LAD: 0.28AggProb: 0.02
AggProb is the Probability of Seeing that Particular Team Win Against That Particular Opponent

World Series

TeamsPwin (Team 1(PloseSeries Prob
ARI vs. TOR0.410.590.00
ARI vs. MIN0.410.590.00
ARI vs. HOU0.390.610.01
ARI vs. TEX0.370.630.00
ARI vs. TBR0.300.700.01
ARI vs. BAL0.320.680.01
MIL vs. TOR0.510.490.01
MIL vs. MIN0.520.480.01
MIL vs. HOU0.490.510.02
MIL vs. TEX0.470.530.01
MIL vs. TBR0.390.610.02
MIL vs. BAL0.420.580.03
LAD vs. TOR0.620.380.03
LAD vs. MIN0.630.370.03
LAD vs. HOU0.610.390.07
LAD vs. TEX0.590.410.04
LAD vs. TBR0.500.500.06
LAD vs. BAL0.530.470.10
PHI vs. TOR0.500.500.01
PHI vs. MIN0.500.500.01
PHI vs. HOU0.480.520.02
PHI vs. TEX0.460.540.01
PHI vs. TBR0.380.620.02
PHI vs. BAL0.400.600.03
MIA vs. TOR0.390.610.00
MIA vs. MIN0.400.600.00
MIA vs. HOU0.370.630.01
MIA vs. TEX0.350.650.00
MIA vs. TBR0.280.720.01
MIA vs. BAL0.300.700.01
ATL vs. TOR0.660.340.04
ATL vs. MIN0.670.330.04
ATL vs. HOU0.640.360.09
ATL vs. TEX0.620.380.04
ATL vs. TBR0.540.460.07
ATL vs. BAL0.570.430.12

Overall Results Table

TeamSurvival ProbSurvival ProbSurvival ProbSurvival Prob