Is Frenchy for Real?

Stop me if you’ve heard this one before: Jeff Francoeur is off to a great start and appears ready to reach his full potential.

It’s now May 9th, and Francoeur is hitting .302/.345/.581. He leads the league in total bases with 10 doubles, a triple and eight home runs. He adds value in the field and on the basepaths. His .279 ISO ranks fifth in the American League, and he ranks fifth from an overall production standpoint with 1.7 wins above replacement. His sharp uptick in productivity is surprising, especially since there is at least one real sign that the improvements might stick.

One of the most interesting aspects of his overall line is how he isn’t walking any more frequently than in years past. The improvement is entirely attributable to a power surge. His batting average on balls in play is by no means otherworldly at .310. His line drive rate is a fairly unimpressive 16%, and nearly 50% of his balls in play are on the ground. Add in that his strikeout rate is a touch higher than it was last year, and it becomes easy to wonder how he is displaying so much power.

The bulk of the answer can be found by looking at his unsustainable 21.1 percent rate of home runs per fly ball. Another part of the answer becomes apparent after analyzing his plate discipline statistics: Francoeur isn’t swinging as much anymore.

Since debuting in 2005, his overall swing rates have ranged from 56 percent to 62 percent. He is currently swinging at just 51 percent of the pitches thrown his way, and most of the dropoff can be attributed to increased selectivity on pitches in the strike zone. Though his O-Swing rate is lower than it was last year, it represents a higher rate than his 2005-09 average, and is still resulting in way more outside swings than the league average. His Z-Swing rate, however, has dropped precipitously from approximately 83 percent over the last six seasons to just 67 percent.

Pitchers are throwing him a steady diet of pitches out of the zone, and he is making more contact. The selectivity on pitches in the zone has also led to an increase in contact. Put it all together, Frenchy is making more contact across the board, while swinging much less than he ever has before. Pitchers are staying out of the zone, likely in an attempt to avoid getting hit hard on a pitch in the zone given his heightened selectivity. We should expect most of this to normalize over the next few months, but it seems hard to believe that his plate discipline stats will shift that substantially. And while his HR/FB will fall as he racks up more plate appearances, it is entirely possible that his new approach will result in a higher ISO — it just won’t remain this high.

His numbers to date got my mind motoring about similar spikes in ISO rates. Francoeur won’t finish the season at .290 or higher, but even a .200 mark would represent a vast improvement on his ~.140 average over the last few seasons. Assuming Francoeur can finish the season with an ISO in the range of .200-.210, how often do batters experience this much of an uptick compared to an established rate? And is the higher ISO sustained in subsequent seasons?

To find out I queried for five-year spans dating back to 1950, stipulating that the batter needed to tally 250 plate appearances in each season of the span. The 5,648 resulting spans were further filtered to mirror Francoeur’s situation as much as possible: the average ISO over the first four seasons of the span was restricted to a maximum of .150, and the improvement from that average to the ISO in the fifth season of the span had to be at least 60 points. Only 109 spans were left when the filters were applied. The group improved from an average ISO of .118 to .200 in the fifth season.

Did it last? Adding in the sixth season of the span, the sample reduces to 98, and the aggregate ISO dropped from .200 to .147. These players experienced a sharp power surge after establishing a specific level, and subsequently fell back down to Earth the next season. The .147 ISO in the sixth season of the span marks an improvement over the .118 average across the first four seasons of the span, but suffice to say the batters didn’t develop some vast new found power ability.

Francoeur seems to be approaching his plate appearances differently right now, but the gaudy HR/FB ratio is playing a substantial role in his power increase. It isn’t out of the realm of possibility that an improved approach will yield better results, but right now his discipline feels more like a narrative used to suggest his current performance is legitimate. The shift in approach is interesting to monitor right now, but the HR/FB is the real story; a more “normal” rate and we’re talking about a .460-.470 slugging percentage.

Is Francoeur for real? Right now, we don’t have enough information to conclude in the affirmative. But we do have some information that indicates the entirety of the improvement is unlikely to be sustained if he has turned the corner.