Gregor Blanco—the San Francisco Giants projected starting left fielder—hit just .244/.333/.344 with five home runs last year.
Andres Torres—the free agent the Giants brought in to compete with Blanco—hit just .230/.327/.337 with three home runs last year.
For comparison, the average major league team received a .260/.325/.431 batting line with 22 home runs from their left fielders last season.
Based on those numbers, left field appears to be a position of weakness for the Giants heading into spring training. Chris Quick of the website Bay City Ball summed up the general sentiment well by writing:
The best way the Giants can upgrade their team is fixing [left field] LF, but that’s almost surely something that won’t be handled until the trading deadline...And stuff like LF should be easily fixable, in a way, since there’s a chance that because the baseline is so low, any upgrade should be, theoretically, easy to attain.
While Torres and Blanco don't have the power bats typically associated with a corner outfield position, they both provide value in less obvious ways that should make the left field situation a strength for the Giants next season.
First, Blanco (.333 on-base percentage) and Torres (.327) got on base in 2012 above the overall league average (.319) and the league average for left fielders (.325). Torres walked in 12 percent of his plate appearances and Blanco walked in over 11 percent of his plate appearances. Thus, while they both hit for low averages in large part because of their high strikeout rates, their excellent walk rates propelled them to have acceptable on-base percentages.
Secondly, Blanco and Torres are excellent defensive outfielders, and a run saved on defense is just as important and valuable as a run created on offense. According to the defensive metric ultimate zone rating (UZR), Blanco was the 15th best defensive outfielder last year and Torres was 33rd.
With Blanco and Torres, the Giants are deploying two players with enough range to play center field in left. While defensive performance is harder to measure than offense given the limitations of the metrics available, both the numbers and the eye test show them to be well above average in the outfield.
Finally, both players create additional value once they get on base. Blanco was 26 for 32 in stolen base attempts and he was credited with being worth nearly four runs with his legs last year. Torres was 13 for 18 on stolen base attempts and was credited with being worth nearly two runs with his baserunning last year.
In 141 total games including 89 starts, Blanco was worth 2.4 wins above replacement (WAR). In 132 games including 101 starts, Torres was worth 1.7 WAR. Thus, they combined for 190 starts and over four wins last season. If the Giants get the same overall production from their tandem of left fielders this season, they won't need to scour the market for an upgrade at the trade deadline.
Blanco and Torres both strike out a lot and don't hit for much average or power. However, they both walk enough to keep their on-base percentages above the league average, play excellent defense and provide value with their speed on the bases.
If you just look at their traditional hitting statistics, you would assume the Giants need to upgrade in left field. However, when you take into account the complete package that both players offer, you can see why the Giants are comfortable heading into spring training with Blanco and Torres competing for playing time in left field and as backups for Angel Pagan in center and Hunter Pence in right.