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This piece originally appeared on BP Boston, Baseball Prospectus' local site for all your Red Sox needs. And be sure to visit BP Wrigleyville and BP Bronx for Cubs and Yankees analysis as well.

For as long as he stays in the major leagues, I am going to believe in Clay Buchholz. If you pushed me hard enough, you could probably even get me to defend his new haircut. Please don’t make me do that, though. Despite the obvious rough stretches throughout his career, there have just been too many flashes of extreme talent to completely write him off. My go-to move has been to point out that we are just about two years from him pitching like one of the two or three best pitchers in baseball for the first half of a season.

Of course, you can’t talk about Buchholz without mentioning the extreme inconsistencies and the injuries. While he’ll always have the potential to go on an amazing run, he also has the potential to throw a run of duds or find himself on the 60-day disabled list. The truth is we will never know what to expect from him start-to-start, and anyone who tells you otherwise is a liar.

With that being said, it’s time to look at what he’s done so far this year, and try to figure out what we can gleam from it moving forward, if anything. While the surface stats don’t paint a pretty picture, the underlying ones show a pitcher who’s having one of the two best years of his entire career.

This early in the season, one or two bad starts can cloud an entire statline, and that is certainly the case with Buchholz. His 4.93 ERA is still suffering the consequences of that blow up start in New York last month. His peripherals tell a different story, though. While he’s always had some of the most impressive stuff in recent Red Sox memory, he’s used it to induce soft contact more than strikeouts over the years. That’s changing this year, with his 10.6 K/9 shattering the marks he’s put up at other points of his career. He’s done this without losing any bit of control, walking just 2.6 batters per nine innings. Put it all together and he’s pitching to a 2.90 FIP. That’s not the only number that tells this encouraging story, either. On Tuesday, Bryan Grosnick wrote about what Baseball Prospectus’ new pitching stats DRA and cFIP say about the Red Sox’ pitchers. Sure enough, the mixed models point to Buchholz being far-and-away the best Boston starter so far.

So, we’ve established what Buchholz has done so far. Now, we need to look at how he’s done it. The first and most obvious thing to look at is his ballooning K-rate. We’ve seen Buchholz put together solid strikeout campaigns before, but never in any way that resembles this. Unsurprisingly, his plate discipline numbers have been off the charts. He’s inducing whiffs on nearly a quarter of his opponents’ swings, surpassing his previous career high of 22.5 percent. The biggest key to this is getting opponents to swing more, especially on pitches out of the zone. His O-Swing% is currently sitting at 34.6 percent, up from a previous career-high of 30 percent in his amazing 2013 campaign. On top of that, they’re making far less contact on those pitches than they ever have in the past. If you needed a sign that his stuff is on another level this season, having opponents chase pitches out of the zone at this high of a rate is as good of a sign as one could ask for.

When you see numbers improve at such a drastic rate, the first instinct is to look for a change in repertoire. Sure enough, Buchholz has indeed made some adjustments in his pitch selection in 2015. The first thing to notice is that he has been relying more on his sinker at the cost of his four-seamer. He’s also completely abandoned the split-finger fastball, replacing it with more changeups.

These changes have worked, and then some. As one would expect, the sinker is leading to more ground balls from Buchholz, but it’s also been part of the reason for his swinging strike rate. Nearly 20 percent of those pitches have resulted in a whiff, per Brooks Baseball. The most effective change in his repertoire, though, has been the increased usage of his changeup. This pitch has carried him this season, with 57 percent of the balls in play off of it registering as grounders while almost 38 percent of swings against it have come up empty. It’s always been a nasty pitch that results in swinging strikes, but he hasn’t thrown it this much since 2011.

While Buchholz’s ERA paints a depressing picture, everything else points to him being amazing this season. Thanks to a couple of slight changes in his repertoire, he’s striking out batters at an unprecedented rate while keeping his walk-rate in check. All of the advanced metrics point to improvement in his ERA down the road. Given his checkered past, it’s impossible to be completely confident in everything staying this good. With that being said, it’s okay to enjoy it while it lasts. There are few pitchers who are as fun to watch as Buchholz when he’s throwing like this.

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"the best Boston starter so far."

and i would be the tallest member of the lollipop guild