Red Sox

McAdam: The mystery of Mookie Betts’ strangely disappointing season

With a roster that is largely the same as the one which won the World Series last year, the Red Sox' 2019 first-half disappointment is largely a puzzle.

But not upon closer inspection.

Of the returning position players, just two regulars -- Rafael Devers and Christian Vazquez-- are enjoying significantly better seasons than a year ago. A third, Xander Bogaerts, is having another fine season and statistically speaking, is marginally ahead of his breakout season of a year ago.

The rest? Regression abounds. J.D. Martinez has experienced a drop-off at the plate, though he still leads the team in homers.

But the biggest step backward has been taken by Mookie Betts, who easily won the American League MVP award last season and in so doing, thrust himself onto the list of best players in the game.

In 2019, Betts' numbers are decidedly average in comparison to past seasons. He's batting more than 80 points lower than a year ago, when he was the AL batting champion. At his current pace, Betts will fall shy of the 30 homer plateau which he reached in two of his three previous seasons. And his stolen bases are off dramatically with just nine as the schedule inches past the halfway point.

About the only aspect of his game that's remained the same is his ability to get on base and score runs -- two vital components, to be sure. Even then, his better-than-average .379 OBP is off considerably from last year's stratospheric .438 figure.

So, what's wrong?