The Baltimore Orioles Are Unlikely To Maintain Their Run Differential Voodoo Magic


If the season ended today, the Baltimore Orioles would find themselves to be winners of the second American League Wild Card berth. Baltimore has been at or near the top of the Wild Card standings for much of the year, so the fact that they could be a playoff team isn’t a complete surprise, but it’s still a bit difficult to believe that a team that has been so bad for so long will finish the job – especially when their run differential (currently minus 47 runs) indicates they might not even be all that good of a team this year.

Pythagorean expectation isn’t a perfect science – teams outperform and underperform these numbers every year – but Baltimore’s current situation looks bleak from a runs scored, runs allowed point of view. For a little bit of context, here’s a list of all the American League teams that are either even or negative in run differential:

TeamDifferentialWin %
Seattle Mariners00.48
Toronto Blue Jays-250.463
Baltimore Orioles-470.541
Kansas City Royals-470.446
Minnesota Twins-860.421
Cleveland Indians-1250.444

Baltimore’s Baseball-Reference page lists their Pythagorean record at 56-66; that resulting .459 winning percentage looks very much in line with the above chart. The most common argument in support of Baltimore’s ability to maintain the winning percentage in spite of the negative run differential has to do with their bullpen and their ability to maintain the lead late in close games. The thought here is their lackluster offense and questionable starting rotation leads to many losses being of the blowout variety, but their rock-solid back end of the bullpen can be counted on to convert nearly every late-inning lead, no matter how slim the margin.

The numbers seem to support this claim too. The Orioles boast a 23-6 record in one-run games (easily the best in baseball) and a 3.01 bullpen ERA (third in the league). Darren O’Day, Troy Patton, Luis Ayala, and Pedro Strop have each thrown more than 50 innings in relief with an ERA under 3.00, and Jim Johnson has been no slouch in the closer role with an excellent 3.14 ERA and a 93% save conversion rate. But these types of numbers don’t hold up around the league.

The Tampa Bay Rays (2.90) and Oakland Athletics (2.93) both have bullpen ERAs that are better than Baltimore’s, but neither has found the same success rate in one-run games (they’re 18-19 and 19-15 respectively). The skill involved in winning a one-run game shouldn’t be dismissed outright, but Baltimore’s sterling record in one-run games is probably better explained by random variation than simple bullpen construction (even if no actual voodoo magic is at work).

Of course, the Orioles certainly could continue to win at their current .541 clip, but their record still appears to be more of a result of a hot start than steady prolonged success. By May 19 the Orioles had jumped out to the AL East lead with a 27-14 record (+20 runs!); they owned the best record in the American League, and trailed only the Dodgers in all of Major League Baseball (by only a half a game). In the three months since then they’ve played sub-.500 baseball with a 39-42 mark (and a -67 run differential).

The Orioles breaking a 15-year playoff drought would be one of the “worst to first” feel good stories that we all love (and cling to) as baseball fans, but in order to do that they’re going to have to buck the current trend and get back to the most fundamental aspect of the game: score more runs than the other team.

Matt Snyder can be reached on Twitter @snyder_matthew.

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