The funny thing is, Andrew McCutchen and Starling Marte are so good the Pirates would be in the conversation for baseball’s best outfield no matter who the third guy was. But more often than not, the third guy has been Gregory Polanco, and Polanco came with enormous hype. He’s had his good days and bad days, his good moods and bad moods, but these days Polanco’s on a tear. A few weeks shy of his 24th birthday, Polanco looks like he might be realizing his potential, with power, a quick swing, and a diminishing rate of groundballs. The more Polanco hits, the better off the Pirates are, and the better are the chances that Polanco really is establishing himself as a quality regular.

An interesting thing about Polanco is that, even when his numbers weren’t great, they were well and good against right-handed pitchers. It was lefties who were giving him fits, and while that’s not too uncommon for a young lefty bat, it was clearly a hurdle for Polanco to overcome. As much as the Pirates believe in and practice positional versatility, they still would’ve loved to not have to keep Polanco platooned. This leads to something that’s really encouraging. Polanco’s numbers, lately, are up. So is something else.

This is a plot from Brooks Baseball, showing the rate of pitches Polanco has seen from righties and lefties over the course of the season. Should be simple enough.

Polanco’s numbers are up at a time in which he’s faced lefties more often. That’s a pretty big shift, leading into a somewhat lefty-heavy August. And in August, Polanco has a 152 wRC+. Might be a coincidence. Might be the Pirates trusting Polanco more against same-handed pitchers. The point is, seeing more lefties hasn’t wreaked havoc on Polanco’s statistics.

And it’s not that Polanco has just been crushing righties so much that he’s offset problems against southpaws. That would be one potential explanation, but that’s not the actual explanation, because Polanco has seen lefties and Polanco has hit lefties. There are signs that Polanco has made that adjustment, the one adjustment that was keeping him from being a legitimate everyday player.

A year ago, against lefties, Polanco finished with a miserable 33 wRC+. He had two extra-base hits, and a number of groundballs. Through this year’s first three months, against lefties, Polanco didn’t have any extra-base hits, but he did have one walk and 13 strikeouts. He slugged .139. The last two months, against lefties, Polanco has slugged .458. He has five walks and 12 strikeouts, and five extra-base hits. Really, he might deserve six — on August 3, Polanco doubled to right off a left-handed fastball in a game that ultimately got rained out, erasing the statistics. In the big picture, it doesn’t matter, but in the little picture, it is hidden further evidence of a successful adjustment made.

It’s notable that the erased double came off a lefty fastball. Polanco pulled it to right, where, previously, he’d had a lot of trouble getting around on left-handed heat. This has been one of the criticisms offered — that Polanco let his swing get too long, such that he was vulnerable against fastballs, particularly those from the same side. Clint Hurdle believes that Polanco has shortened up, and maybe instead of dwelling on a double that no longer officially exists, we can just watch Polanco against a southpaw named Clayton Kershaw.

From earlier in August, this led off a game:

That’s a home run on a fastball Polanco had no problems catching up to. From the sixth inning of the same game:

Now, that’s Polanco flying out short of the track, which isn’t remarkable, but you can see that Polanco just missed. His timing was good, and his swing was good, and he just didn’t get the right part of the barrel on the ball. You don’t want to give him too much credit, since it wound up a can of corn, but Polanco came that close to going deep twice against Clayton Kershaw in six innings. He had no trouble with Kershaw being a lefty. He had no trouble with Kershaw throwing left-handed fastballs. You want to evaluate a hitter by his process, and the process was there for Polanco to be successful.

Earlier in his career, not so much. Lefties gave him problems, and he put a lot of baseballs on the ground. Some of that would’ve been mechanical, and maybe some of that would’ve been psychological, but now Polanco’s in a better place, and he’s driving the ball more in the air. He’s demonstrated that he can spray the ball around. Hurdle sees it as a night-and-day difference, and if Polanco sustains his gains against same-handed pitchers, that’s better for everyone. I guess maybe not Sean Rodriguez or Josh Harrison, but I figure the Pirates are willing to take it.

In general, Gregory Polanco is having better at-bats. In general, he’s doing more with the baseball, in terms of spraying it in the air with authority. In specific, Gregory Polanco has seemingly made a good amount of progress against lefties, and that used to be a major stumbling block. So, do the Pirates have baseball’s best outfield? They never left the conversation, and they’ve always had an argument. Now, the argument’s stronger. When Polanco’s looking comfortable enough against the best starting pitcher in the game, that carries more than a little weight.