Look at the top of the standings and you find the better teams. Look at the top of the leaderboards and you find simple explanations for why the better teams have been successful.
The Boston Red Sox have been successful in part because Mookie Betts and J.D. Martinez rank first and third in baseball in wRC+. The New York Yankees have been successful in part because they lead the majors in home runs. The Houston Astros have been successful in part because their pitching staff leads the majors in strikeouts. The Chicago Cubs have been successful in part because they lead the majors in OBP.
You usually don't have to dig very deep to find positive statistics for baseball's contending teams. We're all familiar with the usual, well-known numbers, and the better a team is, the better it's likely to look in the major categories.
But we also know a couple of other things. One, baseball teams are complicated, and there are plenty of ways to find and make use of value. And two, variety is the spice of life. If we're going to spend the next several weeks focusing on the same assortment of teams in the playoff races, the least we could do is try to talk about them and their strengths in ways we usually don't.
In that light, I've put together a list of 10 key factors for postseason contenders. It's technically a countdown list, but from my perspective, I like them all. These are 10 somewhat under-the-radar factors that have contributed to a given team being as competitive as it is. These aren't necessarily the biggest reasons why any of the following teams have been successful, but I wanted to identify hidden advantages -- interesting advantages that don't get talked about very much.
Some of these focus on entire teams. Others focus on individuals. Also, I haven't included every single team in the hunt, in part because there are more than 10 contenders. Anyway, let's get started with secret success factor No. 10.
10. The Arizona Diamondbacks' strike zone
In theory, every team is supposed to compete with the same basic strike zone. If some team were given a strike zone advantage right off the bat, no one would stand for it. That wouldn't be fair. But, of course, because we have human beings as umpires, strike zones vary. And, more to the point, strike zones can be manipulated.
The Arizona Diamondbacks have been able to pitch to the friendliest strike zone in the majors. A lot of this comes down to pitch framing, which is the catcher-specific art of both preserving strikes in the zone, and getting calls on pitches out of the zone. According to the numbers at Baseball Prospectus, the Diamondbacks' pitch framing has been worth a league-leading 20 runs above average. They've been led by John Ryan Murphy (plus-8.5 runs) and Jeff Mathis (plus-8.0). The pitchers also play a role, since pitchers with command are easier to catch than their wilder peers.
According to the numbers at Baseball Savant, Diamondbacks pitchers have gotten called strikes on pitches around the edge of the zone 53 percent of the time. The league average is 48 percent. It's a subtle thing, but it has made a daily difference.
9. Matt Carpenter popups
I don't know if it's fair to say the St. Louis Cardinals have surged exactly, but they've played better of late, inserting themselves into the wild-card race. And with the Cardinals remaining relevant, there's no bigger reason than Carpenter, who had a .558 OPS in the middle of May. Since then, he has put up an OPS of 1.144 and swatted 30 home runs, and while it's immediately apparent that Carpenter has made good contact, I want to share one particular proxy.
At this moment, there are 152 hitters who qualify for the batting title. Among them, Carpenter has the second-lowest rate of popups per fly ball, behind only the otherworldly Joey Votto. Votto has long starred by this measure, but what I like about Carpenter is that he also has baseball's lowest ground ball rate. He's trying to hit the ball in the air, and he still hasn't been popping up. It's a testament to how good he is at hitting the ball how he wants to. Few hitters in the world possess superior bat control.
8. The Red Sox's high fastballs
As a pitching staff, the Red Sox are toward the bottom of the league in fastball rate. But they rank fourth in baseball in fastball value and fourth in fastball whiff rate. They rank second, behind only the Brewers, in fastball strikeouts.
A big part of the explanation is the Red Sox's fastball philosophy. Their average fastball thrown has been 2.78 feet off the ground, easily the highest average for any team. In a related note, the Red Sox rank first in the rate of fastballs thrown in the upper third of the strike zone.
The Red Sox didn't invent the idea of overwhelming the opposition with high heat, but they are dedicated to the approach, and it just so happens they could approach the all-time record for wins in a season. Hitters might be trying to elevate low pitches more and more, but that only plays into the Red Sox's hands.
7. The Indians' platoon advantage
There shouldn't be anything remotely controversial about the concept of the platoon advantage. Left-handed pitchers are better against left-handed hitters. Right-handed pitchers are better against right-handed hitters. Simple enough.
When the Cleveland Indians have sent a batter to the plate this year, that batter has had the platoon advantage 71 percent of the time. That's the highest rate in baseball, against a league average of 54 percent. Incidentally, the Indians also finished first in this category in 2017 and 2016.
Some of this is about roster management, and some of it is about the fact that Francisco Lindor and Jose Ramirez are both switch-hitters (to say nothing of Greg Allen and Melky Cabrera). You don't always think about the platoon advantage, but this is one way in which the Indians have matched up better against the opposition, just by dint of the flexibility of their roster.
6. Lorenzo Cain's strike zone discipline
When the Milwaukee Brewers signed Lorenzo Cain as a free agent, they cited an internal belief that he'd age gracefully. They might not have figured that Cain would actually improve. He's sitting on a career-high .391 OBP, with a career-high 12 percent walk rate.
Cain has dramatically cut down on his chases out of the zone. When talking about plate discipline, I like to focus on two-strike counts, when discipline is really put to the test. With two strikes, Cain has swung at 92 percent of pitches in the zone. But he has swung at just 25 percent of pitches out of the zone. The difference between those rates (67) is the greatest such difference for any hitter. Almost out of nowhere, Cain has polished his batting eye, and the Brewers have gotten a huge boost from having him at the top of the lineup.
5. The Athletics' high-leverage pitching performance
Why are the Oakland A's where they are? How does a team with such a suspect starting rotation get 23 games over .500? Sure, the lineup has been good, but the pitching has been driven by the bullpen. More precisely, by the back of the bullpen.
High-leverage situations are those in which the most hangs in the balance. The score is close and the bases are loaded, for example. In high-leverage situations, the A's have allowed a league-low .241 OBP. They've also allowed a league-low .283 slugging percentage, and so it follows that they've allowed a league-low .223 wOBA. Those numbers aren't all Blake Treinen and Lou Trivino, but they've been a big part of it.
This is why the A's have worked to bolster the bullpen. They know their bullpen has gotten them into the postseason hunt in the first place. The A's have played a lot of tight games, and when those tight games have advanced to the later innings, the A's have been almost impossible to hit.
4. Kyle Hendricks' swing suppression
I know it has been a challenging year for the Cubs' starting rotation, and I know Kyle Hendricks hasn't always pitched like he did at his peak. Right now he's sitting on a roughly league-average ERA. But still, I want to highlight something that reflects how Hendricks succeeds despite his generally unremarkable stuff.
There are 99 pitchers this year who have thrown at least 100 innings. When Hendricks has thrown a pitch in the strike zone, batters have swung just 55 percent of the time. That's the lowest rate in the pool. Think about it: What could happen when you throw a would-be strike? If the batter swings, he could get out, sure, or he could miss, but he also could do some damage. If the batter doesn't swing, it's basically a free strike.
Hendricks has been earning those free strikes because his command is so good, and because he's so talented at mixing up his timing. Over Hendricks' career, this is one skill that hasn't lapsed.
3. The Braves' early-count aggressiveness
For a while, batters were encouraged to be patient, to be disciplined. And, sure enough, it's good for any batter to swing at strikes and lay off balls. It's all about selectivity. But this is an era when pitchers are better than they've ever been, throwing harder than ever and generating more strikeouts than ever. It's increasingly dangerous for a hitter to fall behind because pitchers these days are lethal when they can sniff a strikeout.
So what has been the Atlanta Braves' strategy? They lead all teams in first-pitch swing percentage. They lead everyone in the rate of swinging at either of the first two pitches, and they lead everyone in the rate of swinging at any of the first three pitches. In terms of just first-pitch swing rate, Freddie Freeman and Ozzie Albies rank second and third in baseball. The Braves have worked to try to ambush their opponents because that way, they might put a ball in play before the opposing pitcher ever gets to his putaway pitch.
2. The Phillies' weak contact allowed
More hours than you might suspect have been dedicated to the study of how much control pitchers have over balls they allow to be put in play. Certain pitchers are surely able to suppress quality contact, but for individuals, it takes a while before a sample size is big enough to be meaningful. That is, again, for individuals. For entire teams, it might not take as long.
The Philadelphia Phillies' pitching staff collectively has yielded a hard-hit rate of 29 percent, lowest in baseball and lower than the league average of 35 percent. Aaron Nola ranks first among qualified pitchers; Jake Arrieta ranks fifth.
Also worth considering is expected slugging percentage allowed, based on Statcast batted-ball information. At .535 on batted balls, the Phillies rank second-lowest in baseball, below the league average of .571. Coming into the year, the Phillies figured they were making some sacrifices on defense. By allowing relatively weaker contact, the impact of their weaker defense has been mitigated.
1. The Diamondbacks' overall team defense
We're coming back to the Diamondbacks. I liked this information so much I had to include them twice. At No. 10, I talked about the Diamondbacks' strike zone while pitching. Here, I want to highlight their team defense. I know there's generally not really anything "hidden" about having a good defense. Still, I do think defensive value is by and large underrated and underestimated. Plus, I want to show off a cool statistic.
First, I'll point out that the Diamondbacks are at plus 84 defensive runs saved, which ties them with the Brewers for first place in baseball. Now let's get even more advanced. Using Statcast information at Baseball Savant, it's possible to see a team's expected wOBA against, on batted balls. It's also possible to see a team's actual wOBA against, on batted balls. The difference between those two numbers should largely reflect the quality of a team's defense. And there are the Diamondbacks in first place, just ahead of the A's. Compared to what the Diamondbacks would be expected to have allowed in terms of wOBA, they've given up the least. So when you wonder how they're hanging around where they are, understand it's a defense-first ballclub. And that defense is terrific.