Philadelphia Phillies pitcher A.J. Burnett struck out 12 batters in Monday’s 3-2 win over the Washington Nationals, thus becoming the first player in major league history to record a 12-K game with five different teams, per ESPN Stats & Info.

Burnett has accomplished the feat with each team he’s played for: the Phillies (2014), Pittsburgh Pirates (2012-13), New York Yankees (2009-11), Toronto Blue Jays (2006-08) and Florida Marlins (1999-2005).

Monday’s was perhaps the most surprising of Burnett’s 12-strikeout performances, as the right-hander hasn’t been particularly effective this season. Not only does he own a 7-14 record and 4.30 ERA, but Burnett’s 7.9 K/9 would be his lowest since 2010 (7.0) if it were to hold up.

In four previous starts against the Nationals this season, Burnett compiled just 17 strikeouts, failing to top seven in any of the outings.

Additionally, the Nats are the hottest team in baseball, having won 12 of their last 14 games, even after Monday’s loss.

That said, the Nationals do have a pit of a weakness for the punch-out, with their 21.1 strikeout percentage ranking 24th in the majors. Of the six teams behind them, only the division-rival Atlanta Braves (22.5 percent) and Miami Marlins (23.3 percent) have a realistic shot at the playoffs.

As for Burnett, the 37-year-old hurler is widely expected to retire after the season, after he contemplated the move heading into this year. Among active players, Burnett’s 2,337 career strikeouts trail only the 2,437 compiled by injured New York Yankees pitcher CC Sabathia.

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