There are an abundance of words I could use to describe the 2017 Cardinals. Allow me to voyage deep into my lexicon to share with you, the ever so gracious reader, a few of my personal favorites:
- Really frustrating
- Really, really frustrating
Perhaps the most agonizing aspect of this team is its streakiness. The Cardinals began the year 3-9 before finishing April on a 9-3 run. That sparked a nine-game road win streak...only to drop four consecutive games at home the very next week. St. Louis rattled off four straight victories in early June to end a seven-game slide. In August, their season-high eight wins in a row were followed by eight losses over the club's next eleven games.
An impromptu Twitter poll produced the expected result: 84% of respondents felt that consistency has "been an issue for the Cardinals offense in 2017".
Cue the hot takes. But first, cue the spreadsheets.
To measure a team's consistency, or lack thereof, I found their game-to-game standard deviations for various offensive categories. The empirical rule states that by pure randomness, 68% of your data should fall within one standard deviation of the mean, 95% within two, and 99.7% within three. For example, the league average standard deviation for wOBA is .0886, or 88.6 wOBA points. We would expect 68% of the individual games to appear within 88.6 points of the .321 mean, 95% within 177.2 points, and so on. I can't stress enough that the empirical rule is a general statement not tailored to this specific data.
If 88.6 points seems extreme, keep in mind that stats for one game are inherently volatile due to the microscopic sample size. Any quantification of a baseball team's consistency on a day-to-day basis is meaningless without context, specifically its relation to the other 29 teams.
Got all that down? Let's take a look at our results.
(Remember that a lower standard deviation indicates a more consistent offense.)
Runs Scored Consistency by Team
We see here that the Cardinals place in the top ten in runs scored consistency and in the top five when scaled to a per-plate-appearance basis. What happens when we use a more advanced metric by applying the principal of linear weights?
Weighted Runs Created Consistency by Team
Again, the Cardinals offense grades out as one of the ten steadiest by either measure. Turning to a stat like wOBA, we find more of the same.
Weighted On-Base Average Consistency by Team
As the astute reader will have realized by now, each of the above tables share one glaring flaw: they don't account for park factors. Up to this point you would think that the Rockies were one of the more erratic clubs in Major League Baseball. Is there something real to Colorado's larger standard deviations or are they merely the product of playing at Coors Field one day and Petco Park the next? Here are the 30 teams ranked by wRC+ consistency, which adjusts for varying park factors and run environments.
Weighted Runs Created Plus Consistency by Team
The Cardinals check in with the seventh lowest standard deviation. Out of pure curiosity, I looked at each team's isolated power (slugging percentage minus batting average) and on-base percentage to determine whether the Cardinals' power or ability to reach base was more consistent. I also threw in BABIP to see which teams experienced more volatile batted ball luck.
ISO, OBP, and BABIP Consistency by Team
While St. Louis' ISO is slightly more consistent than its OBP, both numbers are better than their respective league average marks. It's also worth noting that any dry spells when seemingly no flares drop for a hit are (relatively) few and far between for the Cardinals.
Is a more consistent offense automatically primed to be a more effective one? No. In fact, I found just a 13.6% correlation between wRC+ consistency and actual wRC+ performance.
One thing that I have much more than 13.6% confidence in is this: whatever frustrations stem from the Cardinals offense are the result of an issue over talent and firepower, not inconsistency.