Saturday, November 07, 2020
How 52% becomes 70%
I had a Twitter poll where most of the respondents were incorrect in their guess.
In games played by the Expos over 162 games, 52% of runners on base are from the Expos.
In games played by the Spiders over 162 games, 48% of runners on base are from the Spiders.
When the Expos play the Spiders in a 7 game series, what is the chance the Expos win the series?
The correct answer is 70% and I will explain how to get there.
The Expos batters get on base 13 times per game, with 26 batting outs, while the Expos pitchers allow 12 runners to get on base. In other words, of the 25 runners, the Expos batters generate 52% of them (13/25). The Spiders are the flip side, placing 12 and allowing 13.
In a head-to-head contest, what happens? If Expos generate 52% of the baserunners against an average team, then they’ll naturally generate more runners against the Spiders. Whether you use the Odds Ratio, or the simpler “Strat-O-Matic” method (52+50-48), the answer is 54%. So, right now, we have the Expos batters reaching base 13.5 times and the Spiders reaching base 11.5 times. That’s 54% of the runners being from the Expos. 13.5 times reaching base is an OBP of .342, and that’s the Expos OBP. The Spiders OBP is .307. The ratio of OBP of Expos/Spiders is 1.1145.
Runs scored to allowed is proportional to the square of the OBP ratio. So, the square of 1.1145 is 1.242. That’s 1.242 runs score per runs allowed.
Wins to losses is proportional to the square of the Runs ratio. So, the square of 1.242 is 1.543. That’s 1.543 wins per losses (or a .607 win%).
Win/loss ratio of a 7-game series is (roughly) proportional to the square of the Wins ratio. So, the square of 1.543 is 2.38. That’s 2.38 series wins per 1 series loss. And that’s 70%
And so, when one team generates 52% of the runners facing another team generating 48% of the runners, then over a 7 game series, the better of such teams will win 70% of the time. That’s the sliver of difference between teams, when those scoring confrontations get to compound into a series win.
Recent comments
Older comments
Page 1 of 150 pages 1 2 3 > Last ›Complete Archive – By Category
Complete Archive – By Date
FORUM TOPICS
Jul 12 15:22 MarcelsApr 16 14:31 Pitch Count Estimators
Mar 12 16:30 Appendix to THE BOOK - THE GORY DETAILS
Jan 29 09:41 NFL Overtime Idea
Jan 22 14:48 Weighting Years for NFL Player Projections
Jan 21 09:18 positional runs in pythagenpat
Oct 20 15:57 DRS: FG vs. BB-Ref
Apr 12 09:43 What if baseball was like survivor? You are eliminated ...
Nov 24 09:57 Win Attribution to offense, pitching, and fielding at the game level (prototype method)
Jul 13 10:20 How to watch great past games without spoilers