Looking at the Astros chasing the Rangers and Mariners for a playoff spot
Is it better to be the hunter or the hunted? As it pertains to baseball playoffs, I’m pretty sure I prefer the “hunted.” That would mean your team has taken the W/L lead. But given that the Mariners and Rangers have stumbled of late, the Astros find themselves in the former posture. And, compared to the Astros’ position one month ago, it’s better than looking like an also-ran.
First, let’s look at the playoff odds. Between the last wild card spot and the division championship, the Astros’ overall playoff odds are decent. But the odds of winning the division are challenging.
Fangraphs Playoff Odds Astros (53%) Mariners (56%) Rangers (18%)
PECOTA Playoff Odds Astros (61%) Mariners (34%) Rangers (43%)
Fangraphs Division Odds Astros (42%) Mariners (46%) Rangers (11%)
PECOTA Division Odds Astros (48%) Mariners (30%) Rangers (22%)
As you can see, the Baseball Prospectus model is higher on the Astros than the Fangraphs model. Furthermore, the Fangraphs model is more favorable to the Mariners and quite down on the Rangers.
Regression Theater
Let’s look at how the Fangraphs model sees the three teams. All three teams generally have under performed in terms of offensive runs scoring. The Mariners have over performed in terms of suppressing runs allowed, but the Astros and Rangers have under performed in terms of runs allowed. The percentage increase or decrease, below, shows the expected regression toward expectations for the rest of the season.
Rest Of Season Percent Change
Runs Scored/Game Runs Allowed/Game
Astros RS +3.9% RA -8.9%
Mariners RS +12.8% RA +3.6%
Rangers RS +2.2% RA -1.3%
So far the Astros lead the three teams in runs scored per game (4.54) and are expected to increase the pace of runs scoring in the rest of season. The Mariners have been the worst at scoring runs (3.74 runs per game) and have no where to go but up. The Astros, on the other hand, have allowed the most runs of the three (4.64) but are expected to regress toward a lower R/G in the rest of season. The Mariners have been great at suppressing runs (3.87 runs per game), but the model projects some regression for the rest of season.
Runs Planning Committee
So far, the Astros haven’t planned their distribution of runs very well. The Astros are -2 on PythagenPat. This is refined version of the Pythagorean W/L record. The Mariners meanwhile are +2. The PythagenPat says that the Astros, Rangers, and Mariners should be essentially tied (Seattle and Rangers at 26-28 and Astros at 26-27). Why then are the Astros entering today trailing both the Mariners and Rangers? Bad Luck? Poor managing? The baseball gods? Take your pick.
Base Runs
Base Runs estimates how many runs should have been produced or allowed based on the offense’s actions on the field. In a sense, this explains whether the in-game sequencing has been better or worse than expected. Between offense and pitching results, the Astros are -3 on Base Runs and should have a winning record, 27-26, based on the Base Runs estimate. The Seattle results exactly equal its Base Runs, and the Rangers are -2 on Base Runs. Like the PythagenPat estimate, the Astros and Mariners should be tied and the Rangers 1 run behind them.
What does this all mean? There are a bunch of games to be played, and the odds will ebb and flow. But the Astros need to be aggressively chasing the AL West leaders.