The Postseason Is A Two-Strike Game, And Other Observations From The MLB Playoffs


As we near the end of the second round of Major League Baseball’s expanded playoffs, we thought it would be a good time to delve into what we’ve observed in this year’s unusual postseason. In some ways, bracket baseball is similar to past Octobers — but it’s also been filled with surprises. So what have we learned? And what does it all mean for the league championship series and World Series?

The Dodgers are overwhelming favorites

The Los Angeles Dodgers have established themselves as a powerhouse over the last decade. They have won eight straight division titles and advanced to two of the last three World Series. And yet they entered October with one of the longer World Series title droughts in the majors, not having won one since 1988. But this might be their year.

Entering play Friday, our model has the Dodgers with a 54 percent chance to win it all. No other club had better than a 14 percent chance. For comparison, since we reintroduced our Elo ratings in 2015, no other team had greater than a 34 percent chance of winning the World Series at a similar point in the postseason (either entering, or early in, the division series round).

The Dodgers have few real weaknesses, particularly if starting pitcher Walker Buehler can get beyond his blister issues. (He said he “felt great” following his Tuesday start, but he struggled with command.) The club ranks third in position player wins above replacement,1 and fifth in pitching WAR. They bolstered their star-laden roster last winter with the addition of MVP contender Mookie Betts, but they also have developed plenty of homegrown talent — success stories like Tony Gonsolin, who started as a ninth-round pick out of St. Mary’s College and has been one of the game’s best starters this season. The Dodgers have the stars and depth to win it all.

Bullpens keep gaining work, but more depth is required in these playoffs

In recent years, starting pitchers have generally taken on less and less work. Generally speaking, that’s true to an even greater degree in the postseason. This postseason, starting pitchers are again accounting for fewer pitches, throwing just under half of all pitches (49 percent), the lowest postseason share during the pitch-tracking era.2 Teams are less willing to allow starters to pitch deep into games and increasingly turning to unconventional strategies. For instance, in the second game of their division series, the New York Yankees elected to use an opener (it didn’t work).

Before the playoffs started, we wondered if fewer off days in this postseason might mean that teams would find it more difficult to lean on their best pitchers, which would advantage teams with deeper staffs. Four teams — the Dodgers, Houston Astros, Tampa Bay Rays and St. Louis Cardinals — entered the playoffs with nine or more relievers enjoying ERA+ marks of 110 or better, meaning these pitchers were performing at least 10 percent better than league average in terms of run prevention. Two of those teams (Dodgers and Astros) have advanced to the league championship series, while a third (Rays) is one win away.

Expanded playoffs reward lesser teams

MLB commissioner Rob Manfred said last month that he’s in favor of making aspects of the expanded playoffs permanent. He added:

“… People love brackets and love picking who’s going to come through those brackets. I think there’s a lot to commend it. It is one of those changes that I hope becomes a permanent part of our landscape.”

If the expanded playoffs are like the NCAA Tournament, the Miami Marlins were the Cinderella team, advancing into the second round. While the Marlins finished above .500 (31-29), our Elo ratings rank them as a below-average team: They were outscored by 41 runs in the regular season, ranked 27th in pitching WAR and 26th in position player WAR. Two clubs with losing records, the Milwaukee Brewers and Astros, made the postseason. Expanded fields bring excitement and extra TV cash, but the trade-off is that the bar to reach the postseason would be lowered when it comes to team performance in a normal 162-game regular season. (And it’s worth noting that, other than following the strike-shortened 1981 season, MLB playoffs have never shrunk in size — only grown.)

The postseason is increasingly a two-strike game

Two-strike counts have gradually increased in the pitch-tracking era: The percentage of pitches thrown with two strikes has exceeded 29 percent in each of the last four regular seasons. As velocity continues to increase, batters have swung and missed more and more, and foul balls have increased. The number of foul balls surpassed balls in play in 2017, and more balls were hit out of play than in play for the fourth consecutive season this year. And the percentage of two-strike pitches is typically greater in the postseason, as the quality of teams and pitchers is generally better.

This postseason, 30.3 percent of pitches have come with two strikes, the second greatest share of the pitch-tracking era (trailing only the 31.6 percent mark of last postseason). So that ought to make two-strike hitting more important than ever. In the wild card round, four of the top five teams in two-strike weighted on-base average, and six of the top eight, advanced on to the division series round. In the regular season, the Braves, Dodgers, Padres and Yankees had four of the top five overall weighted on-base marks, and four of the top five marks with two strikes. While these teams may simply have more talented lineups, six of the nine teams with the smallest gap between overall wOBA and two-strike wOBA made the postseason. In the age of more strikeouts and two-strike counts, putting the ball in play is a market inefficiency.

The Tampa Bay Rays keep unearthing stars

The Rays have long enjoyed a reputation as an innovative underdog. They’ve been living up to that reputation, extracting a ton of value from players they acquired in recent trades en route to the best record in the American League. They have done it again with one of the breakout stars of the postseason: outfielder Randy Arozarena.

The 25 year old was hardly a household name when he was acquired by the Rays from St. Louis in a trade back in January. But he emerged this season to post a 176 wRC+ over 76 plate appearances, which would have ranked sixth in the majors if he had enough plate appearances to qualify. His underlying skills suggest he’s no fluke, as his quick bat currently ranks 29th in average exit velocity on line drives and fly balls (96.8 mph) among hitters with at least 25 batted ball events this season. He’s been even better in the postseason in a number of areas, batting .500 with a 1.042 slugging mark in the playoffs entering Friday, and giving the Rays — who ranked in the top 10 in batting and pitching WAR — yet another potential star.

Check out our latest MLB predictions.