Quick one today -
The Nats have had the worst NL offense in May easily. (OPS in May is .639. Cincinnati is 2nd worst at .651). One very simple reason is that they can't hit. Their average is 3rd lowest in the NL (.231 tied with CIN, slightly above CHC at .226). When you can't get hits - you can't get enough XBH and you can't get on base enough.
So if they get more hits everything would be ok, right? Well... there are two other problems. They don't get on base enough regardless of hits and they don't hit for power when they do hit.
May BB% : 7.3% 10th in the NL
May ISO* : .110 14th in the NL.
(*SLG-BA : taking the singles out of your slugging percentage to see how you really "slug")
Even if the Nats were to have had a league average batting average in May they wouldn't be hitting with enough power or taking enough walks to have a good offense.
This is where the injuries really hurt. LaRoche (out a big chunk of May) had an walk rate of 14.2% (projected in the 11% range) and an ISO of .190 (proj : .175ish). Bryce 8.8% (proj: 10.5%) and .133 (proj: .210). Zimm 8.1% (proj : 9.2%) and .273 (proj : .195).
(I put the projections just because small sample size is skewing those actual numbers - Ryan Zimmerman doesn't have Ruthian power. )
As far as the back-ups go, McLouth might walk enough. Moore might hit for enough power. Frandsen might hit for average. But that's it. You lost 2 of your best hitters for average in Bryce and Zimm and maybe replaced it with 1 guy who can match that. You lost 3 of your best power hitters and maybe replaced it with 1 guy who can match that. You lost 3 of your most patient batters (and the Nats may only have 4 "patient batters") and maybe replaced it with 1 guy who can match that.
You brought in Greg Dobbs.
This isn't terribly odd when moving from starters to back-ups. They are back-ups for a reason. The Nats had a lineup coming in with 4 good-great hitters (Werth, Desmond, Bryce, Zimm), 1 good hitter (LaRoche), 2 could be good hitters (Ramos, Rendon) and one defense first guy (Span).
In May the Nats :
Lost 2 good-great hitters for whole month
Saw the other 2 good-great hitters struggle to be good**
Lost the 1 good hitter for a big chunk of time
Saw neither could be good hitters even be average (ramos has been bad, Rendon worse)
Well at least the defense first guy is hitting about average!
**Oh you thought it was just Ian? What if I told you Ian had a better May than Werth? OPS .783 to .702. Werth is hitting and getting on-base but only has 3 XBH - 2 doubles and a homer. Desmond isn't hitting but is getting on-base ok (same # of walks as Werth) and hitting for power - 2 doubles, a triple and 5 homers.
What's gone wrong in May offensively? Everything.