MLB roundup: Reasoning behind Pomeranz trade; Wainwright's brilliance

Stark: Red Sox paid a big price for Pomeranz (1:01)

Jayson Stark reacts to the Red Sox's acquisition of Drew Pomeranz for 18-year-old Anderson Espinoza, who Stark says has been compared to Pedro Martinez. (1:01)

Drew Pomeranz averages more pitches per plate appearance than all but two starting pitchers who currently qualify for the ERA title, and some rival evaluators wonder whether his tendency to surrender walks is a habit that will hurt him more against lineups in the American League East, which are generally better than the ones he saw in the NL West this year.

But the Boston Red Sox paid heavily for Pomeranz because their scouts believed that the changes he made in his pitch selection -- more cutters and curveballs -- have staying power, and because they recognized the uncertainty in the trade market. The deadline is just 15 days away, and for the most part, one executive noted, the market for starting pitchers is largely undefined.

Nobody knows whether the White Sox will change course and listen to offers for Jose Quintana, or whether the Dodgers' starting pitching deficit will become a surplus as Clayton Kershaw, Brett Anderson, Alex Wood and others return to their rotation and suddenly provide some trade options for L.A.'s front office. Nobody knows whether the Yankees will sell or buy, or whether the Braves will lower their asking price on Julio Teheran, given how they have listened to offers on him the past two seasons. Nobody can say for sure whether the Twins will change their minds and be willing to kick in money to help offset the salary of Ervin Santana, who is an attractive option but is owed about $33 million for the rest of this season and the next two.

So rather than wait, the Red Sox decided to move aggressively past that uncertainty and deal for what they considered to be the best available market option in Pomeranz, giving up highly touted 18-year-old Anderson Espinoza, widely regarded as one of baseball's best pitching prospects.

The deal was somewhat surprising, because the Red Sox may not have needed the best available starter.