After putting their 2012 struggles behind them in 2013 with a World Series title, the Boston Red Sox find themselves in an all-too-familiar territory: On pace for a 90-loss season. Since 1962, the first year that both the American and National Leagues expanded to the current 162-game regular season schedule, there have been two teams -- the 1976-78 White Sox and the 1997-99 Cubs -- that wrapped a pair of 90-loss seasons around a 90-win campaign. Boston is set to become the third.
But unlike two years ago when the pitching fell apart, it's the club's offense that has become a black hole: The Red Sox have scored the fewest runs in the American League, hitting a collective .243/.316/.368 en route to posting a paltry .301 wOBA. For comparison's sake, last season the Sox hit .277/.349/.446 with an MLB-leading .347 wOBA.
While a lot of the club's offensive futility rests on the shoulders of disappointing veterans and stopgaps, a pair of highly anticipated rookies have struggled mightily during their first extended action in the big leagues. Twenty-one-year-old shortstop Xander Bogaerts is hitting .232/.297/.349 and 24-year-old center fielder Jackie Bradley Jr. has hit .214/.288/.285.
With both players still locked into extended struggles -- Bogaerts is hitting .181 since June 1 and Bradley is back after getting demoted to Pawtucket -- it's time to start thinking about their respective futures. In other words, is there any precedence that suggests that Bogaerts and/or Bradley can turn into valuable big league bats?
Using Baseball Reference's Play Index, since the beginning of the Live Ball Era (1920) there have been just 12 players (not including Bogaerts) who entered their age-21 season with their rookie eligibility intact and posted an OPS+ between 65 and 85 while receiving at least 450 plate appearances (Bogaerts is at 81).
Of those 12, two finished their respective careers as above-average hitters (one of which ended in the Hall of Fame), three were roughly league average offensive performers, and the remaining seven were well below-average. The chart below illustrates the three groups, as well as OPS+ totals through their 20s as well as their final career mark.
It bodes well for Bogaerts that nearly half of the group went onto become established offensive contributors, but it shouldn’t be too surprising either given that younger debuting players are often considered better prospects. There are, however, a few patterns to note:
1. Minor league power appears to be incredibly important among the 12. Five players posted Isolated Power totals above .120 prior to their big league debuts; four of those five -- Chet Lemon, Marty McManus, Jose Guillen and Wil Cordero -- went on to become solid or better bats. And the fifth player, Zoilo Versalles, won the AL MVP in 1965. Bogaerts, for the record, owns the highest minor league ISO mark among the entire group, at .193, nearly 30 points higher than Lemon (.163).
2. Four players -- McManus, Guillen, Cordero, and Versalles -- posted an ISO north of .100 during their age-21 seasons; Bogaerts owns a .117 mark.
3. Of the five successful big league bats, four took tremendous leaps in production during their age-22 season, seeing a jump of at least 17 points in OPS+. In contrast, only one player -- Chris Speier -- took a similar development step forward during his second season among the below-average group. So Bogaerts' work next year looks like a vital step for his future success.
History has shown that not all struggling 21-year-old rookie bats are doomed. But, unfortunately, the precedent isn't quite as strong for Bradley.
Again, using Baseball Reference's Play Index, there were 51 players since the start of the Live Ball Era that were rookie-eligible 24-year-olds who posted an OPS+ between 55 and 75 and received at least 350 plate appearances (Bradley is at 62).
Of the 51, just three players -- Hall of Famer Luke Appling, Bill Robinson and Brady Anderson -- posted a career OPS+ above 100 (league average); four others -- Rich Aurilia, Whitey Herzog, Kevin Young and Mickey Witek -- own career marks above 90. Otherwise, the remaining 44 players were well below-average performers.
Appling, Anderson and Robinson all took tremendous jumps during their age-25 season, but so did nine other players, none of whom panned out during their careers. None of the seven solid performers slugged over .343 during their rookie seasons or ran a whole lot or even showed solid patience at the plate. Each did, however, perform well enough coming up through the minor leagues, but so did Chris Snyder, A.J. Hinch and Brian Anderson, a trio that belongs to the below-average group.
So, what exactly does history say about the futures of Bogaerts and Bradley? The odds definitely tilt towards Bogaerts, no surprise given his age and above-average power in the minors. He's continued to hit for decent pop in the majors with 26 doubles and nine home runs.
As for Bradley, the probability that he develops into even a manageable big league bat certainly seems like a long shot; just 14 percent of players to struggle in a similar manner during their age-24 season have gone on to become successful bats.