Kimbrel’s Season For the Ages

Craig Kimbrel is putting the finishing touches on one of the best reliever seasons in history. He has struck out 113 of his 226 batters faced this season, producing a 50% strikeout rate that nobody with 30+ innings in a season has matched or exceeded.

In fact, nobody has ever thrown 30+ innings with a 45% strikeout rate either. Kimbrel isn’t merely en route to establishing a new record. He is about to blow right by the existing record, which was set in 2003 by Eric Gagne. Gagne struck out 44.7% of the opposition in his Cy Young campaign. Only two other relievers have even topped 44% throughout history: Aroldis Chapman‘s 44.4% rate this season, and Kenley Jansen‘s 44.0% rate last year. While relievers face such a small sample of batters, and another strikeout or two could materially affect the strikeout rates in question, Kimbrel still has a commanding lead. He has simply been unhittable this season and may have established the new benchmark for evaluating relief pitching performance in this era.

Kimbrel has thrown 61.1 innings over 61 appearances this year — both of which are down relative to his oft-cited over usage last season — and has allowed a whopping 26 hits. He has a .245 BABIP against and a 92.6% strand rate. His latter rate leads the league by a full two percentage points. He has also only walked 14 batters this season, which represents the third straight year in which his walk rate dropped. His walk rate was 18.2% in 2010, 10.5% last year, and now 6.2%, which is low before even comparing it to a gaudy 50% strikeout rate. His 8.07 K/BB ratio ranks 2nd all-time among pitchers with at least 30 innings and a 40% strikeout rate: Sergio Romo‘s 70 punchouts against five walks last season has him beat.

One of the biggest reasons Kimbrel wasn’t going to succeed like this was his control: he didn’t have much of it as he progressed through the minors. Whether it be his own work, the tutelage of Roger McDowell, or both, Kimbrel has become a strikeout juggernaut that rarely gives up hits, limits free passes, and strands almost everyone that reaches.

His 1.03 ERA is far and away the lowest among senior circuit relievers. Chapman is in 2nd place at 1.55. Kimbrel also has a ridiculous 0.84 FIP to his name, which is not only substantially lower than Chapman’s 2nd-place 1.51 mark, but happens to be the lowest of all-time. Kimbrel’s 0.84 FIP narrowly edges Gagne’s 0.85 FIP in 2003.

Let’s not stop at the raw rates either, as changes in the scoring environment have made it tougher to score runs over the last few years. Context is key in any analysis and production relative to the league is more important than quoting raw numbers. Kimbrel has a 26 ERA- and a 22 FIP-. Gagne had a 30 ERA- and a 20 FIP- that season. Gagne logged more innings in 2003 — 82.1 to Kimbrel’s current total of 61.1 — but the two were essentially equals from a rate perspective.

Kimbrel has also kept balls on the ground at a 48% clip, up from last year’s 44% rate, and way up from his 28% rate as a rookie. He isn’t an extreme groundballer, but his rate is solid, especially in the context of his other rates. It has been historically tough to put a ball in play against Kimbrel this season, and almost half of the batters who didn’t strikeout or walk batted the ball on the ground. Be it weak contact or hitting the ball directly at fielders, a .245 BABIP with ~50% grounders is a very fruitful combination.

It’s difficult to evaluate relievers with WAR, especially across different eras, given the overall change in reliever usage. Relievers pitched more even 10-12 years ago, let alone 20-25 years ago, and WAR is a counting metric. Gagne’s 4.5 WAR is over a full win greater than Kimbrel’s 3.4 WAR, but that shouldn’t, in any way, invalidate what he has done this season. When great pitchers throw more innings, they produce more overall value.

However, a closer look at the post-1995 reliever leaderboards shows just how much per-inning value Kimbrel has generated this season. There have been 10 relievers with 3.4+ WAR in a season since 1995 and, aside from Kimbrel’s current season, the other nine ranged from 74.2 to 107.2 innings. That Kimbrel has produced 3.4 WAR with 13 fewer innings than anyone else in that leaderboard is remarkable.

Strictly using WAR, Kimbrel’s season might not seem like one for the ages. But he is literally doing things that nobody else in baseball history has either done, or come close to doing. That is the mark of a truly special pitcher, and a truly special season.

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Eric is an accountant and statistical analyst from Philadelphia. He also covers the Phillies at Phillies Nation and can be found here on Twitter.

45 Responses to “Kimbrel’s Season For the Ages”

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  1. Preston says:

    Kimbrel was probably the best reliever in baseball a year ago. This season not only did he increase his already staggering K rate, but he did it while nearly halving his walk rate and increasing the amount of GBs he generated. Simply amazing.

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    • lonewolf says:

      He was the best reliever not named Sergio Romo a year ago. He is the best reliever this year.

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      • NeverJamToday says:

        I disagree. Sergio Romo is eliminated from the discussion because the Giants insist upon using him as a ROOGY. In contrast, Kimbrel faces LH batters more than 50% of the time, and he’s even tougher against them.

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      • Preston says:

        I didn’t say categorically he was the best reliever. I said probably, he did lead in WAR. although the above article articulates why that is not the best metric for measuring a reliever. If there was one reliever who I would argue was better a year ago it was probably Mariano Rivera.

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  2. TKDC says:

    Is there an objective way of comparing his dominance in rate stats this year to 1999 Pedro? Or did I just commit heresy by bringing that up?

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  3. midgley's folly says:

    what a year to be a braves fan! between chipper’s historic final year, medlen’s emergence, heyward’s resurgence, and kimbrel’s ridiculosity, there’s a lot to be giddy about.

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  4. stupup74 says:

    Craig Kimbrel has been incredible this season. He has anchored the best bullpen in MLB for the last two years. He literally changes the game. He is the Cy Young winner in my mind. Hands down.

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    • I Agree Guy says:

      He’s not the Cy Young winner in my mind.

      Hands down.

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      • Anon21 says:

        Yeah, if he had even thrown a lot of innings for a reliever, I’d say it’s a discussion worth having, but…

        Instead, I’ll just appreciate this wondrous season for its own sake.

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      • I Agree Guy says:

        That I can agree with.

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    • vivalajeter says:

      I’d much rather have 230 innings of RA Dickey than 60 innings of Kimbrel.

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      • nilbog44 says:

        So would everyone else. Doesn’t mean he hasn’t been incredible and it doesn’t make this article any less interesting.

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      • bblackwell says:

        Is the Cy Young award a Most Valuable Pitcher award? Or should it go to the best pitcher? You could very well come up with different answers to either question.

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      • vivalajeter says:

        nilbog, I was responding to a poster who said that Kimbrel was a hands down CY Young winner. I wasn’t taking anything away from the article itself.

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      • yeah says:

        Nilbog is goblin spelled backwards!!!

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  5. hummbaby22 says:

    How come people never mention Dennis Eckersley’s 1990 when it comes to dominant reliever seasons anymore?
    WHIP 0.607
    SO/BB 73/4(!):
    ERA+: 603 (!!)

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    • bstar says:

      Good point, hummbaby (is your name a reference to the late 80’s Roger Craig “hum, baby” Giants teams?).

      Kimbrel is on pace for setting records for all slash numbers against except OBP. Craig is at .185 for OBP but Eck put up years of .172 and .175 in 1990 and 1989 respectively. That’s what walking 7 batters in 130+ IP over two years will do for you.

      Kimbrel also is unlikely to touch Eck’s WHIP record for relievers that you cited.

      But he’s on top in everything else.

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  6. I wrote a blog post on Kimbrel as a rotation anchor for 2013. Check it out here.

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  7. TKY says:

    It was McDowell! But why? Why McDowell?

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  8. Matt says:

    I found this article very interesting, however you committed one of my biggest pet peeves from fantasy writers. You said:

    “He has also only walked 14 batters this season, which represents the third straight year in which his walk rate dropped. His walk rate was 18.2% in 2010, 10.5% last year, and now 6.2%”

    In fact, his walk rate has only dropped the last two years, from 2010 to 2011 and from 2011 to 2012, not the last three. I understand that three years gives the trend more credibility, but it’s false. Matthew Berry does this all the time and it bugs the heck out of me.

    I don’t mean to nitpick, I did enjoy the article. I was just wondering if others felt the same way about this issue.

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  9. Nivra says:

    Considering that K rates have consistently gone up over time, it seems logical that Kimbrel’s K-rate should be compared relative to his peers rather than absolutely, with respect to history. Is Kimbrel’s K%+ better than Gagne’s K%+?? I’d bet they’re very close to similar, which makes Gagne’s season even that more impressive. I’d say the difference in WAR between the two seasons is justified.

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  10. Neal says:

    As a Braves fan I can’t help but wonder what kind of trade value Kimbrel would have this off season. Coming off a great season in 2011 and a historic season in 2012 his value could never be higher. He has no injury history and 3 more years of team control.

    I doubt Wren would move him under any circumstances but after seeing Venters regress so quckly it would make me sick to see it happen to Kimbrel.

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    • Anon21 says:

      Given reliever year-to-year volatility, I think making Kimbrel available is absolutely the right move. But I think Wren would be crucified by the Atlanta sports media (such as it is) if he moved Kimbrel in anything other than a ludicrously favorable deal.

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  11. GTW says:

    The most incredible stat I’ve heard all year in regards to Kimbrel is that he hasn’t allowed more than 1 hit in any of his 62 appearances. 26 hits scattered over 26 of his 62 games.

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    • Dave G. says:

      It’s incredible but it also shows how a dominant pitcher can be dominant for 1 inning. How many 2 inning appearances does he have?

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  12. Micah says:
    Wrote a piece on Kimbrel’s cy young chances with historical comps and analysis

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  13. Phantom Stranger says:

    He’s amazing at consistently hitting the lower right corner of the strike zone away from lefties. There is practically nothing a lefty can do against it except foul the pitch off, unless they want to completely sacrifice covering the inside half of the plate.

    I do think Brian McCann falls in love too much calling breaking balls with Kimbrel. Once in awhile from a game theory perspective, every pitch called in a at-bat should be a fastball.

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  14. glenstein says:

    It’s also worth noting, as these strikeout records get broken, that hitters as a whole are striking out at a greater rate than they ever have in history.

    For most of history the K/9 rate was around 3 to 5. The first time in history the K/9 hit 6.0 was in 1967. It didn’t happen again until 1987.

    Then starting in 1994, the K/9 was 6.2. Every year from 94 to ’08 the K/9 has been above 6.0. Then the K/9 hit 7.0 in 2009, 7.1 in 2010, 7.1 in 2011 and 7.6(!) this year.

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  15. iallm says:

    Just don’t walk around the locker room with a Q-tip in your ear Craig.

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  16. David says:

    One thing that never gets much publicity is that Kimbrel was mentored by Billy Wagner during his year with the Braves. He credits a lot of his improvement to Billy, and it’s hard not to give that theory at least a little credence. His control numbers improved dramatically immediately following that season (whereas his BB/9 numbers had been downright AWFUL at every level before).

    Just thought it was an interesting tidbit. Kimbrel is, after all, basically just Billy Wagner throwing with his right arm (and now better than Billy ever was).

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  17. Calvin says:

    14 players have posted a higher K% over a season than Kimbrel’s 50.2. The second and third highest TBFs are.. 23 and 11. K-Rod’s nickname-earning debut was the 23.

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