The current landscape in the AL East, as usual, is obscene. The Red Sox, in first place, have a run differential of +69. The Yankees, in second place, are +75. The next-best mark in the league is +35, and the next-best after that is +12. Despite so many storylines floating around that the Red Sox and Yankees are in trouble, each has been wildly successful.
Yet, despite their success, they haven't been able to shake the Tampa Bay Rays. The Rays, like the Red Sox, got off to a terrible start, but the Rays, like the Red Sox, have gotten way better ever since. Since dropping to 1-8, the Rays have posted the second-best record in baseball, and currently sit just four games out of the division lead, and two games out of the wild card.
If you glance quickly at their numbers, it doesn't look like they belong. Offensively, the Rays have been below average in runs, OPS, and wOBA. By no means have they been terrible, but hitting has not been a strength.
On the mound, meanwhile, the Rays have been below average in strikeouts, home runs, and FIP. As with the offense, Tampa Bay's pitchers as a group haven't been bad, but they haven't been especially good, either - certainly not good enough to carry a team to a 35-30 record.
So at this point, when considering how the Rays have stayed in the race, we're left with two options:
(1) They've been lucky
(2) They've played really sweet defense
When you go into the numbers, it ain't #1.
At Fangraphs, you can see that the Rays are currently leading the league in UZR. But hey, all right, no biggie; a lot of people don't trust UZR very much. So why don't we go to simple BABIP against? It's an easy, intuitive measure of how many balls in play allowed have turned into hits, and it stands to reason that a good team defense will let fewer balls in play turn into hits. That's the best definition of "good team defense."
The Rays' BABIP against is .266. The next-best is .277. The league average is .291.
Let's break things down further by analyzing individual batted-ball types, shall we? This data comes from Baseball-Reference.com:
Split | League BABIP | Rays BABIP | Rays Rank |
Ground balls | 0.232 | 0.195 | 2 |
Fly balls | 0.138 | 0.122 | 6 |
Line drives | 0.713 | 0.687 | 4 |
Overall | 0.291 | 0.266 | 1 |
The Rays' defense has been strong across the board, turning all types of balls in play into outs more often than the league average. This suggests excellent work by both the infield and the outfield. In other words, BABIP and UZR are in agreement - the Rays' defense has been awesome.
If you look around the active roster, the fact that the Rays have been playing great defense isn't surprising. Casey Kotchman, Ben Zobrist, Evan Longoria, B.J. Upton, Sam Fuld, and so on - there are a lot of excellent defenders, here, and it's all come together. It hasn't necessarily all come together at the plate, but it's all come together in the field, which is only another means by which a player can help his team win.
I'm not sure that the Rays have what it takes to surpass the Red Sox or the Yankees over the remainder. They are, by most measures, the inferior team. But their defense has helped to keep them within striking distance, and it should only continue to be a strength. A couple of breakthrough performances at the plate or on the mound, then, may be all they need.