5 Oakland A's stats to leave behind as we enter the second half of 2015

The Oakland A's just began the second half of their 2015 season, and thank goodness for that because the first half was tough to watch. Realistically, the postseason is probably out of reach. Even if you agree that the roster is better than its record, the hole they've dug for themselves might be too big to climb out of -- nine games under .500, 8½ out of the AL West with four teams ahead of them, and 8 out of the Wild Card with the maximum 11 possible teams between them and the top spot. The good news, as Jeremy mentioned this morning, is that the A's are an AL-best 27-20 since May 23 with a plus-61 run differential, but if they want to make an historic comeback they'll have to be great for a couple months rather than just good.

Fortunately, there's enough time left that we can still dream if we want to. We can remember that the 2012 A's entered the second half nine games out of first place, and went 51-25 the rest of the way to capture the division crown. We can remember that last year's Angels finished on a 60-31 charge, with Matt Shoemaker pitching like an ace and reliever Cory Rasmus making six starts to finish the year. Or that the 2014 Royals went 41-23 to finish last season. And if your reaction to those examples is that those teams were good and this one isn't, well, remember that the A's have the best ERA and the fourth-best run differential in the AL, and that they score the 10th-most runs per game in all of MLB. They aren't the powerhouse that the 2014 first-half A's were, but they're close enough that if they get hot they can make some serious noise.

So, with that in mind, here are 5 stats to leave behind in the first half as we enter the final 71 games.

Base Runs: 12 wins worse than expected record

Base Runs is sort of like a fancier version of a Pythagorean record. Instead of just looking at total number of runs scored and allowed, though, it looks deeper to see the individual performances of the hitters and pitchers to find an expected record. From the Fangraphs glossary:

The key here is that there's no evidence that teams can control when they get their hits and walks. A good team gets on base more than a bad team, but clustering their hits together for six weeks doesn't mean they'll do it for the next five months. ... Base Runs helps here because it takes into account a team's performance without considering the sequencing to calculated expected runs scored and runs allowed, and then takes those numbers to generate expected wins and expected losses.

Pythagorean record says that the A's plus-44 run differential should have led to a 50-41 record, nine games better than reality. But Base Runs says the A's should have been 53-38, a full dozen wins better than they actually did. The only team with a better expected record by Base Runs is the Dodgers at 55-35, with the Astros matching Oakland's 53-38 mark. Instead, they are where they are, 12 games worse than they possibly deserve. No other team is more than six games worse than their Base Runs record, and the Twins are nine games better than theirs.

Will the A's turn that mark around and start putting together some real wins instead of theoretical ones? That could depend on whether they can fix some of these following stats.

One-run games: 8-22 record

Anytime two teams play a close game, there is always a small element of luck involved. Sure, you would expect the better team, with the more consistently productive hitters and the stingier bullpen, to win a majority of them. But there's always a "stuff happens" variable to one-run contests, where a grounder can hit the wrong pebble and take a funny hop, or a hitter can get jammed but accidentally place a perfect flare in front of two charging outfielders for the key two-run single. Your best player can make an uncharacteristic error at the worst moment, or an umpire can mistakenly call back a home run and change everything.

The A's are 8-22 in such games, which means that they're 33-28 in games that have a more clear winner. (They're also 17-8 in blowouts of five runs or more, which means they're twice as likely to smash their opponent as vice versa.) The only teams who have come close to that level of futility in one-run affairs: the Blue Jays are 10-18, and the Phillies are 9-16. However, the Phillies shouldn't really count because that's actually an improvement over their overall record, so they're doing better than normal in one-run games.

The first step to turning around that first-half record will be turning around this record in one-run games. They have left far too many winnable contests on the table. Of course, this particular weakness might not be a complete fluke if you also consider how bad the bullpen has been.

Bullpen is 21-18 vulnerable games

This is a stat I have been tracking this year, so if you've already heard me explain it then you can skip to the next paragraph. A "vulnerable game" is my definition for one that is decided by the bullpen one way or other. Any tie game is vulnerable, since it will be won or lost with a reliever on the mound. A close lead is vulnerable if at any point a reliever has to earn a hold or a save. And a non-vulnerable game can become vulnerable if the pen gives up enough runs to blow it (or to make things close enough that a hold/save becomes necessary).

Oakland's pen has found themselves in 40 such games. They have sealed 21 of those, and they've lost 18 of them. The other of those 40 games was initially blown by the pen, but then the offense re-took the lead and the reliever sealed it the second time around, so it's not counted in the successes nor the failures. Now that they've at least converted more than they've blown, we can no longer say that this has to get better. There is historical precedent for a bullpen losing half of its close games, and in fact neither their 12 blown saves nor their 17 relief losses* lead the Majors -- the Braves (21), Rays (19) and Mariners (18) have more relief losses, and five teams including the Astros have racked up more blown saves.

* The 18th loss by the pen was charged to the starting pitcher based on his inherited runners scoring

But shouldn't it get better? Relievers work in tiny samples so they're volatile, and even good ones can look bad for a while. Clippard and Pomeranz seem to have stabilized the final two innings, and Pom finally gives them a viable lefty. Otero appeared to rediscover himself in Triple-A and could be good again. Rodriguez has struck out 14 of the last 26 batters he's faced and allowed hits to just three of them. Scribner is probably not going to pitch important innings anymore, so his 11.75 strikeout-to-walk ratio makes him one of the better low-leverage options in the league. Venditte is on the road to recovery. There's no guarantee that any of Mujica, Abad, or O'Flaherty will turn things around, but if one of them does then even better.

And of course, one thing that would help the pen is if the defense would shape up behind them.

4th-worst defense in MLB

Oakland ranks 27th according to Fangraphs' position-adjusted Defense value, at negative-17.4 runs. They also lead the league in errors by a big margin, though, so they must be doing something well to not rank last in total defense. But will the glovework continue to be this bad?

The conversation starts with Marcus Semien, of course. He's still making errors, with four already in July, but he's also improving visibly as time goes on. Brett Lawrie was a mess to start the year, but he's looking much better at third base. Ike Davis is back at first instead of Max Muncy. Both catchers are defensive strengths.

The biggest surprises, though, and the guys we should really be talking about, are Josh Reddick and Ben Zobrist. Both rank as negative defenders on B-Ref and Fangraphs, and Zobrist clocks in as the worst non-Butler defender on the team on both sites. Again: Ben Zobrist has been the worst fielder on the team, and Josh Reddick has been a negative in RF. If you want to know what's wrong with the defense, there you go. And although Burns' diving catches have looked pretty, he's rated as neutral on B-Ref and among the worst on the team on Fangraphs. If you're wondering why Sogard and Fuld play so much, it's because the A's need defense so badly that it's worth adding a 60 OPS+ to the lineup.

So, it's up to you. Will Zobrist get better as he gets further away from his recent knee surgery. Will Reddick start making some big plays? Will Semien continue to sharpen up, and is Lawrie finally locked in? It's hard to believe this group could play worse defense than they already have, so by definition it has to get at least a bit better, right?

And of course, if it doesn't, then remember this. The teams directly above the A's in Fangraphs' Defense rating are, in ascending order: the first-place Yankees (-14.0), the Wild Card-leading Pirates (-11.5), the Indians, and the second-place Astros (-8.1). You can survive with a bad defense if you hit and pitch well, and the A's do both of those things. Well, as long as they aren't facing an opposing lefty starter.

5-17 record against left-handed starters

Nobody in MLB has a worse win percentage than Oakland against left-handed starters, but eight teams have worse OPS marks against southpaws overall (the White Sox are nearly 96 points beneath Oakland) and nine clubs have fewer homers (two are still in single-digits, with the A's at 17). The A's are only striking out twice for every walk against lefties, and Phegley, Lawrie, and Butler should give them some thump in their favorable platoon matchups. This seems like another thing that probably went worse than it should have, and now Jake from A's Farm is here to provide some insurance runs.

***

The first half was a bummer. The defense was bad in unexpected ways, which probably helped contribute at least a little to the bullpen under-performing, which led to the team losing way too many of its close games, which resulted in a record of 41-50 instead of, potentially, 53-38. Oh, and along the way they got shut down by almost every lefty starter they faced, even though they aren't even close to being the worst-hitting team against lefties. How many of those things will continue, and how many will the A's leave behind in their rear-view mirror? We'll begin to find out tonight.