Is Tigers' rookie sensation for real?

From the SweetSpot mailbag, a question about the American League's most surprising rookie:

    A lot of attention has been lavished upon Jason Heyward, with good reason. In 274 PA he's hitting .266/.383/.489 with 11 home runs (and Rookie of the Month honors in both April and May).

    Meanwhile, Brennan Boesch seemes to being largely dismissed, especially amongst sabermetric people, due to his high strikeout rate and high BABIP. True, he was the AL's Rookie of the Month in May, but pretty much everyone thinks it's all a fluke.

    He's currently hitting .348/.393/.628 with 9 home runs in 178 PA. His BABiP is .390, which is probably unsustainable but even if it regresses the power will still be there, and it's not like he's hitting a lot of bloop singles. He's hitting the ball hard, and his stikeout rate is actually lower then Heyward's. Can Boesch be considered a real long-term threat, comparable to Heyward?


    Detroit, Mich.

Boesch has been phenomenal. With a few more plate appearances -- at the moment he's 24 short of qualifying for the percentage lists -- Boesch would sport the fifth-best OPS in the American League and the second-best slugging percentage (behind teammate Miguel Cabrera). Boesch has been a slightly better, more valuable player than Heyward this season.

Still, in almost every way they're not particularly comparable. Boesch is not a particularly good left fielder; by most accounts Heyward is a fine right fielder (or will be). Boesch was an afterthought this spring, and didn't join the big club until a few weeks into the season; Heyward was one of the biggest stories in spring training.

Which gets at the biggest point of comparison ... Boesch is four years older than Heyward, which makes a monumental difference when rating two players' long-term prospects.

So let's forget about Heyward, and answer the interesting question: Is Brennan Boesch anywhere near this good, really? Historically, Boesch has never been much of a prospect, advancing one level every season despite generally unimpressive numbers. Last year in Double-A, he slugged .510 but also posted a .318 on-base percentage. There's simply nothing in Boesch's statistical record suggesting that he's good enough to play everyday in the majors. Let alone rank among the league leaders for an entire season.

Which doesn't mean he won't. Human beings have this odd way of surprising us. It's just not the smart way to bet.