Odds of Winning the Division

Posted by on Aug 16, 2019 in Baseball

We’re now in the home stretch of the my baseball simulation league season, and I thought it might be fun to try to run some numbers to see what the odds are for each team to win their division.

Most sites that calculate these sorts of probabilities (FanGraphs, Baseball Reference, Baseball Prospectus, and FiveThirtyEight) do so by running thousands of simulations (maybe using Diamond Mind Baseball) to determine how often a given team wins the division. I tried to come up with a different method that just uses the raw numbers from the standings to spit out some odds.

I’m looking at how good your team is, how many games back you are, and how many games are left in the season. No, it doesn’t take into account remaining home/road games or strength of schedule or how many games left against teams in your division or anything like that. I’ll leave all the micro-split analysis to others. Micro-split analysis is pretty much all you hear these days from the sportscasters, and most of it is bullshit.

Here are the data points:

a) team record (PCT)

b) Pythagorean Winning Percentage (PY PCT, which uses run ratio, not differential, because a team that wins a game 1-0 is better than a team that wins a game 10-9)

c) number of games behind in your division (GB)

d) number of games left in the season (GL)

And here’s how it works:

Talent = (PCT + PY PCT) / 2
[Uses both record and run ratio to better approximate how good a team is.]

Urgency = MIN(GB / GL, 1)
[I calculate it this way to avoid any division by zero errors and to hard-set a value of 1 for any teams that have been mathematically eliminated.]

Chance = Talent * (1 – Urgency) ^ 10
[The exponent of 10 is arbitrary, but seems to produce probabilities that are similar to the ones created for MLB teams on FanGraphs. The result is a raw number that has little meaning until it is normalized by the last step.]

Win Division % = Chance / SUM(Chance for all teams in the division)
[Normalizing the numbers so that all the numbers in a given division neatly add up to 100%.]

The results, updated through 8/15/2019:

AA EAST W L PCT GB FOR AGNT RD PYPCT GL Talent Urgency Chance Win Division
Maumee 85 43 0.664 740 553 187 0.63 40 0.647 0 0.647 97.60%
Margaritaville 72 57 0.558 13½ 672 611 61 0.543 39 0.551 0.346 0.008 1.20%
Welland 71 57 0.555 14 654 626 28 0.52 40 0.538 0.35 0.007 1.10%
Parkville 66 63 0.512 19½ 612 610 2 0.501 39 0.507 0.5 0 0.10%
Long Island 56 72 0.438 29 670 745 -75 0.452 40 0.445 0.725 0 0.00%
Harlem 45 83 0.352 40 515 637 -122 0.404 40 0.378 1 0 0.00%
AA NORTH W L PCT GB FOR AGNT RD PYPCT GL Talent Urgency Chance Win Division
Atlanta 77 51 0.602 709 562 147 0.605 40 0.604 0 0.604 71.20%
Kitchener 74 55 0.574 595 571 24 0.519 39 0.547 0.09 0.213 25.20%
Hemingway 66 62 0.516 11 612 605 7 0.505 40 0.511 0.275 0.02 2.40%
Great Lakes 65 64 0.504 12½ 602 678 -76 0.446 39 0.475 0.321 0.01 1.20%
Brooklyn 49 79 0.383 28 552 730 -178 0.375 40 0.379 0.7 0 0.00%
Golden State 48 80 0.375 29 616 800 -184 0.383 40 0.379 0.725 0 0.00%
AA SOUTH W L PCT GB FOR AGNT RD PYPCT GL Talent Urgency Chance Win Division
Houston 75 53 0.586 645 579 66 0.549 40 0.568 0 0.568 66.10%
Malibu 71 58 0.55 750 652 98 0.564 39 0.557 0.115 0.163 19.10%
Texas 69 59 0.539 6 658 591 67 0.549 40 0.544 0.15 0.107 12.50%
Coconut Grove 64 64 0.5 11 604 619 -15 0.489 40 0.495 0.275 0.02 2.30%
Camden 48 80 0.375 27 628 724 -96 0.435 40 0.405 0.675 0 0.00%
New Hampshire 36 93 0.279 39½ 438 691 -253 0.303 39 0.291 1 0 0.00%
AA WEST W L PCT GB FOR AGNT RD PYPCT GL Talent Urgency Chance Win Division
Tokyo 78 50 0.609 707 564 143 0.602 40 0.606 0 0.606 48.10%
St. Croix 77 52 0.597 674 594 80 0.558 39 0.578 0.038 0.39 31.00%
Compton 74 54 0.578 4 800 646 154 0.597 40 0.588 0.1 0.205 16.30%
Merced 70 58 0.547 8 754 705 49 0.531 40 0.539 0.2 0.058 4.60%
Tallahassee 57 72 0.442 21½ 631 658 -27 0.481 39 0.462 0.551 0 0.00%
Jersey City 47 81 0.367 31 569 656 -87 0.435 40 0.401 0.775 0 0.00%
NA EAST W L PCT GB FOR AGNT RD PYPCT GL Talent Urgency Chance Win Division
San Jose 71 58 0.55 559 532 27 0.523 39 0.537 0 0.537 82.10%
Chicago 63 66 0.488 8 667 673 -6 0.496 39 0.492 0.205 0.05 7.60%
South Beach 61 67 0.477 496 487 9 0.508 40 0.493 0.238 0.033 5.00%
North Port 60 68 0.469 10½ 549 558 -9 0.493 40 0.481 0.263 0.023 3.50%
Chillicothe 59 70 0.457 12 562 575 -13 0.49 39 0.474 0.308 0.012 1.80%
Parry Sound 43 86 0.333 28 499 702 -203 0.349 39 0.341 0.718 0 0.00%
NA NORTH W L PCT GB FOR AGNT RD PYPCT GL Talent Urgency Chance Win Division
Seattle 88 40 0.688 650 408 242 0.701 40 0.695 0 0.695 94.20%
Amherst 78 50 0.609 10 660 529 131 0.6 40 0.605 0.25 0.034 4.60%
Montreal 75 54 0.581 13½ 592 492 100 0.584 39 0.583 0.346 0.008 1.10%
Buffalo 68 61 0.527 20½ 512 525 -13 0.489 39 0.508 0.526 0 0.00%
St. Catharines 63 66 0.488 25½ 478 508 -30 0.472 39 0.48 0.654 0 0.00%
Columbus 50 79 0.388 38½ 434 549 -115 0.394 39 0.391 0.987 0 0.00%
NA SOUTH W L PCT GB FOR AGNT RD PYPCT GL Talent Urgency Chance Win Division
Mud Creek 77 51 0.602 603 509 94 0.577 40 0.59 0 0.59 97.10%
Cleveland 64 65 0.496 13½ 631 581 50 0.538 39 0.517 0.346 0.007 1.20%
First State 64 65 0.496 13½ 551 556 -5 0.496 39 0.496 0.346 0.007 1.20%
St. Louis 61 68 0.473 16½ 531 561 -30 0.475 39 0.474 0.423 0.002 0.30%
Tortuga 59 69 0.461 18 593 612 -19 0.486 40 0.474 0.45 0.001 0.20%
Currituck 48 81 0.372 29½ 481 629 -148 0.38 39 0.376 0.756 0 0.00%
NA WEST W L PCT GB FOR AGNT RD PYPCT GL Talent Urgency Chance Win Division
North Liberty 76 53 0.589 549 493 56 0.549 39 0.569 0 0.569 54.20%
Graettinger 74 55 0.574 2 589 524 65 0.553 39 0.564 0.051 0.333 31.70%
Iowa 71 58 0.55 5 530 525 5 0.504 39 0.527 0.128 0.134 12.70%
Cuyahoga County 64 65 0.496 12 578 559 19 0.515 39 0.506 0.308 0.013 1.20%
Long Beach 59 69 0.461 16½ 428 458 -30 0.469 40 0.465 0.413 0.002 0.20%
Birmingham 48 80 0.375 27½ 423 600 -177 0.345 40 0.36 0.688 0 0.00%

Odds change each day as the end of the season draws nearer. Anyone who’s already been mathematically eliminated will show 0%, and those who are on the verge will be way down there.

Also, these numbers might make it easier to objectively decide when to close up shop for the season and start rebuilding for the future. This guy recommends that at the trade deadline, “If you have more than a 15% playoff odds, then BUY. Else SELL.”

Might expand this later to try to figure out what each team’s odds are of being a wild card, getting to the playoffs, or winning the championship.

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