Who is the best pitcher in baseball right now? For a long time — maybe since he won his first Cy Young Award in 2011 — the answer has been pretty easy: Clayton Kershaw.

The answer on June 29, however, may be Max Scherzer. Or maybe Chris Sale. Or still Kershaw. Bill James says it’s Scherzer. He has a formula on his website that attempts to answer this question, and right now Scherzer holds the slightest of edges over Kershaw, having passed him with a 10-strikeout gem on June 16. Since then, Scherzer has had two more dominant outings while Kershaw suffered the first four-homer game of his career. After giving up zero runs in six innings and striking out eight in his last start, Kershaw will try to stay on track in Thursday’s game against the Los Angeles Angels.

James’ system rates the starter’s previous game more heavily than his next-to-last start, and that one more heavily than the one before. It doesn’t ignore the past. A pitcher’s last 23 starts count for 50 percent of his total, and what he did before that also counts 50 percent. Kershaw first topped the leaderboard in May 2013. Although Scherzer had a couple short stints at the top, Kershaw had led since July 7, 2015.

It’s hard to argue against Scherzer at the moment. He has a 2.06 ERA with just 65 hits allowed in 113 2/3 innings with 151 strikeouts. That’s 5.15 hits per nine innings, which would break Nolan Ryan’s record of 5.26 for a starting pitcher. The two-time Cy Young winner is pitching the best baseball of his career, in a season in which scoring has gone up. He has a 1.69 ERA over his past 11 starts while allowing a .148 average.

Kershaw, meanwhile, has already allowed a career-high 17 home runs. Yes, even the great Kershaw is giving up bombs in this year of the home run. It’s so perplexing that his ERA has risen all the way to 2.47. Yes, we’re about to nitpick a guy with a 2.47 ERA. That’s how good Kershaw has been. A small blip, and we freak out.

So I looked at all 17 home runs to see what’s going on.

April 3, Dodger Stadium: Ryan Schimpf (seventh inning, 0-0 fastball)

I’m sure Kershaw thought nothing of this Opening Day home run. The score was 12-1 at the time, he threw a first-pitch fastball, and Schimpf ran into a ball near the top of the strike zone and yanked it out to right.

April 8, Coors Field: Nolan Arenado (first inning, 2-2 curveball)

Kershaw was visibly disgusted with this one, shaking his head as he got a new ball, I think because he felt the pitch got too much of the plate. Dodgers announcer Orel Hershiser called it a hanger, pointing out that Kershaw hadn’t pitched at Coors Field in 2016 and that maybe that’s a pitch that breaks bigger at sea level.

April 8, Coors Field: Mark Reynolds (sixth inning, 1-0 fastball)

The catcher set up inside, but Kershaw left a fastball right over the middle of the plate and Reynolds hit a towering fly ball out a couple rows into the center-field bleachers, a two-run shot that gave the Rockies a 3-1 lead.

April 8, Coors Field: Gerardo Parra (sixth inning, 1-1 fastball)

Parra followed with another home run to center field, off another fastball down the pipe, the first time in his career Kershaw had allowed back-to-back home runs and just the third time he had allowed three home runs in a game (one of the others had also come at Coors Field). OK, no big deal at this point: A couple bad pitches plus Coors Field and these things can happen.

May 1, Dodger Stadium: Hunter Pence (first inning, 1-1 curveball)

This was a surprise. Pence is now 8-for-73 against Kershaw in his career, a .110 average, with one home run. This was it. Not a bad pitch, but Pence guessed right for once and hit it out to left field.

May 1, Dodger Stadium: Buster Posey (third inning, 2-1 slider)

Kershaw yelled in anger as this one left the park, a flat slider that stayed up and in, and Posey pulled it out to left for his third career home run off Kershaw. (Adam Dunn is the only player with four home runs off Kershaw.)

May 6, Petco Park: Ryan Schimpf (eighth inning, 1-0 fastball)

Late in the game, Kershaw may have been tiring a bit, and Schimpf hit a 90 mph fastball into the first row in right-center. Pretty good location on the pitch, however, right at the bottom of the zone (this is the lowest pitch hit off Kershaw for a home run this season). Kershaw also barked at the plate ump after this one, believing his first pitch should have been a strike.

One explanation for the home run barrage is that hitters, with their uppercut swings, are simply getting better at hitting the low pitch. Kershaw has been burned more often on low pitches this season. He has allowed 104 home runs since 2010, and here’s the breakdown by vertical location: