There is a record chase going on in the Bronx this season.

There won’t be live cutaways on “Baseball Tonight” or daily updates in newspapers, and at least one of the key players involved was not even aware of it until he was told about it on Thursday.

Still, the Yankees’ bullpen is making history, as its 11.3 strikeouts per nine innings is on pace to be the highest rate in modern history. Five bullpens from the 19th century averaged more, but they combined to throw only 19 innings.

“Obviously we enjoy strikeouts, but I wasn’t aware of that,” Dellin Betances said after being asked about the record. “There’s a lot of games left. We have to continue to stay with the same mindset of being aggressive and putting our team in a good position to win ballgames.”

Betances is averaging 16.2 strikeouts per nine innings, trailing only teammate Andrew Miller (16.6) for the major-league lead among pitchers who have thrown at least 30 innings. The pair joins closer Aroldis Chapman, who is averaging 13.7, to form a trio that has been the driving force behind this chase.

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There is some fine print here, considering strikeouts are at historic highs across the board. This season, pitchers are striking out 8.0 batters per nine innings, potentially making this the 10th straight season a record is set. Relief pitchers are averaging 8.6 strikeouts per nine innings, which also is a record.

This does not change the fact that the Yankees’ bullpen essentially has been in a class of its own in the strikeout department this season. The gap between the Yankees and the third-place Mariners (10.0 strikeouts per nine) is bigger than the margin between Seattle and the 16th-place Dodgers.

The Yankees mostly have the “Big Three” of Chapman, Miller and Betances to thank, as they have 56.7 percent of the bullpen’s strikeouts despite pitching in just over 40 percent of its innings. More importantly, they are a huge reason the Yankees’ bullpen has been effective this season, as they have a combined ERA of 2.30 in 94 innings, compared to the 5.06 ERA in 138 2⁄3 innings the team’s other relievers have posted.

Overall, the Yankees’ relievers are 15th in the majors in ERA (4.00) but rank fifth in terms of win probability added, according to statistics from the website FanGraphs.com. Win probability added measures a player or unit’s effect on a team’s overall win expectancy, and despite the mediocre ERA, the Yankees rank highly because their best pitchers generally have pitched in the most important spots.

Chapman, Miller and Betances have accounted for 69 1⁄3 of the 80 1⁄3 innings the Yankees’ bullpen has pitched in late and close situations, according to Baseball-Reference.com (the seventh inning or later with the batting team tied, ahead by one, or with the tying run at least on deck).

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Said Betances: “We just to try go out there and do our best and hope for the team to win.”