The Nats offense is problematic. It's hard to see it that way as it should end up as one of the Top 3 scoring offenses in the National League, but as I explained before there's a couple points that are ignored by just looking at RS/G. One point is how much the offense is Bryce Harper dependent. Another point is that while the Nats are in the Top 3, the distance between the league average and the top teams is the smallest it's been in years. A third point is that distribution of runs scored matters. It's this last point that I'll tackle today.
Usually when you deal with trying to figure out how many wins a team "deserved" you look at their Pythagorean Record. This takes the runs they've scored and the runs they've allowed and projects a winning percentage. But the statistic breaks down when your runs scored or allowed doesn't follow the usual distribution.
For example, let's say you are a team that alternates scoring between 0 runs a game and 20 runs a game. Game 1 you score 0 runs, Game 2, you score 20. Game 3, 0, and so on. Let's say it happens for a whole year. The pythagorean method will see a team that averages 10 runs a game and probably project that the team should have 145+ wins or something. But obviously the team will have something very close to 81 wins, as it can't win a game it scores 0 runs in and will almost certainly win every game where it scores 20 runs. The pythag will say the team is 60+ games "unlucky" but that's very far from the truth. The Nats "should" have 85 wins by the pythag. Were they unlucky? Or is that far from the truth?
Let's take a look at the distribution of runs scored for the Nats. How many times did they score 0 runs and what are the chances of winning that type of game? How many times for one run, etc. etc. It's still not perfect by any means, but it can correct for odd distributions of runs scored, as we see in that extreme example I noted above. What do I see when I do that for the Nats? I see an offense that should have won, based on the distribution of runs scored in a game, 80 games. (79.97 to be exact). The Nats have won 80 games. We can do the same with pitching and it shows the same thing based on the runs allowed. The Nats should have won 80 games (80.394) and they have.
The reason this works is that basically scoring your first run does little to help your chance of winning, and the same goes for scoring your 8th run and beyond. You are certain to lose a game you score 0 runs in. Adding 1 run to go from 0 to 1 and you are still almost certain to lose that game (~91% chance). You are almost certain to win a game you score 7 runs in (like ~85%) Adding one run to go from 7 to 8 (or 8 to 9, etc.), barely improves those chances. Basically scoring that 8th run and beyond pads your expected win total. Which team in the NL has scored 7 or more runs the most times? The Nats. 37 times.
Does this really mean the Nats haven't gotten unlucky, though? Well it depends how much you buy into luck as a factor. By ignoring the actual distribution the pythag method of win expectation is implicitly assuming a distribution close to expected for your RS and RA, and a random distribution of RS and RA per game. In other words you don't bunch your RS/RA at the high and low ends and you don't happen to match up your high scoring games with your low allowed score games. Either of those situations skew the results. But let's look at those assumptions
Is the distribution of RS and RA in individual games random? This has been looked at and the answer is yeah, pretty much. Let's call this the "Jack Morris" point. Teams don't seem to score more when they allow more, or score less when they give up less. Or looking at it the other way, they don't seem to allow more when they score more, or allow less when they score less. The distribution of runs does appear to be close to random. So in that the pythag has things right.
Is the bunching of RS (or RA) unusual? This is less clear. If a starter is doing poorly runs can come around very quickly. It's known that HRs tend to bunch. Also teams tend to use their worst pitchers in games that get out of hand. You have a big deficit, you trot out the bad pitchers on a team, the soft underbelly. If they fail you tend to follow with even worse pitchers. It would stand to reason that there are times/teams that can bunch runs, at least on the high end.
But then there is another thought that I have and it's harder to pin down. Each batter has a chance of doing well against each pitcher and for the most part it has to do with how the pitcher is doing that day. Bryce Harper has a certain chance to hit "On Scherzer" and a certain chance to hit "Off Scherzer", as does Dan Uggla. These chances are certainly going to be overwhelmed in an individual at bat by other factors, but in a game or certainly accross several games, you can imagine it stabilizing. At this point here no one can hit and you lose. At that point there everyone can and you win. Now assuming that, what if your team is made up of players all at a similar level of offensive talent? If that were the case rather than a slow shift from where you can't hit to where you can, that shift may be dramatic. When certain pitchers cross certain thresholds the combined effect on the line-up could be like flipping a switch. That type of line-up would tend to see bunching. It's kind of like the "type of hitter" idea, where if you have the same type of hitter you may be easier to pitch to by good pitchers, but based on talent, not approach. I don't know if this is measurable. I don't know if it's measurable if it's something. But if it is something then the Nats, as a team that bunches RS on the high end and has more games scoring 2 or fewer than expected, may have it. I don't know I'm definitely rambling now.
Anyway this is all a way to say the offense wasn't necessarily "ok" this year, despite the Top 3 ranking it'll end up with. It didn't outscore opponents in a way you'd normally expect given it's ranking because of the unusual grouping of teams this year. It also didn't score runs game by game in a way that you'd normally expect, instead scoring runs in bunches which isn't as helpful to winning as having a lot of 3-4-5 run games. Is this something to worry about next year? Will the offense be boom and bust again? Was that a product of injuries? Good questions Let's look at part 2 though, first. How the offense is taking Bryce out of it.