At the moment I'm writing this, the Tampa Bay Rays are sitting at the bottom of the AL East with a disastrous 31-46 record. Last year they won 91 games and barely made any moves in the offseason. That brings up the obvious question of what went wrong? Not a lot can be explained, but here's what can.
One of the biggest reasons for the slide is a combination of bad luck this year and good luck last year. Take James Loney for example. Last year he hit .299/.348/.430. This year it's down to .278/.338/378. So what changed? Last season Loney had a batting average on balls in play of .326, which is down to .308 this year. In other words, last year he got the breaks, blooped balls in, beat out infield hits and got broken bat seeing eye singles.
An even better example of this is Wil Myers. Last year, he hit .293/.354/.478 and cruised to the Rookie of the Year partially because the voters lost their minds.*
*That should have been Jose Iglesias's award. For bizarre reason, the voters decided to vote for the guy with the best future rather than the player who actually had the best season. Yes, I know Iglesias's hitting was unsustainable but that doesn't change that for one year he was better than Myers.
Sorry about that, but anyway, Myers is hitting a paltry .227/.313/.354 this year, with a big reason to that being luck, or, the copious amounts of it he had last year. Last year he hit .362 on balls in play It's down to .282. He's an extreme version of Loney. This isn't saying at all that Myers can't have a good career, but last year might not have been the greatest reflection of the player he is at this moment.
In fact, you can apply that to a lot of players on the Rays. Along with Myers and Loney, who are the most obvious because they had such good seasons last year, Yunel Escobar and Desmond Jennings, have both decreased their BABIP from last year.
Another reason is father time. It's inescapable. Ben Zobrist is finding that out this year. He turned 33 in May and is currently having his worst season since 2010, with numbers in almost every category below his career averages. His isn't bad luck either, he has the lowest line drive rate since 2008, while he's hitting more ground balls than ever.
Finally they're probably the best terrible team this year. They're losing games, but some of that is equated to bad luck. Their run differential is just minus 39, and while that may seem like a lot, compare it to the D-Backs, (32-47 minus 66) or the Padres (32-44 minus 64) and it's looking pretty good. In fact, the Rangers are 35-40 and have a run differential of minus 46. The Rays are terrible, there's no denying that, but at least now it's somewhat explainable.