TWISL: Deadball vs. Modern Pitcher Value Test

Goals

Here are the things I’d like this league to be able to contribute to:

1. Increase our understanding of pitcher value — specifically as defense effects overall performance: but more importantly we will look at stats like RA/9 instead of ERA, and we’ll calculate OAV and WHIP with errors counting as hits to get a true feel for how teams are impacted, since the effect of errors doesn’t show up in the traditional pitching stats (ERA/OAV/WHIP).
2. How many more errors will a team of deadball pitchers allow over a team of modern pitchers?
3. What effect will the increase of errors (if any) have on team performance?
4. How big of an advantage (if any) do teams with deadball pitchers have over teams with modern pitchers?
5. Have fun!

League setup

24 teams (12 owners with 2 teams each). Salary: $80 million · AAA: No · WW: No · Clones: Allowed · Trades: No · DH: No

Team composition. Every owner submits two teams. Offense: both teams must share the same offense — draft whatever hitters you want, but both teams must have identical offenses, with at least 1,000 PA carrying a HR/100# of 5 or greater (to incorporate the HR-suppression value deadball pitchers provide). Pitching: one of your two teams can only draft pitchers from 1888–1919; the other can only draft pitchers from 1985–2016 — keeping people from taking advantage of 2017–2020 not using dynamic pricing and upsetting the value test, while still leaving 31 seasons of pitching options for both rosters.

Ballpark. Any ballpark may be used, but both teams must use the same ballpark.

Alignment. Two groups for the test — Group A (Deadball Pitchers) and Group B (Modern Pitchers), 12 teams each. Each league had 6 of each group, each division had 2 of each group. Each owner had 1 team in each league. Alignment was random and adjusted as needed to meet the conditions above.

Results: traditional stats

First, here are the league-average traditional stats:

From this it would appear the deadball pitchers had a slight value advantage. For the same $ spent on pitching staffs, the deadball pitchers had a lower ERA, same OAV, and allowed less HR. Once we add in the effect of errors, though, we have the following:

Results: adjusted stats (including errors)

This result led to the following:

Deadball W: 81.42 · Deadball W%: 0.502
Modern W: 80.67 · Modern W%: 0.498

100+ win teams: 2 modern, 2 deadball. 90–99 win teams: 4 modern, 4 deadball.

Now, there were four teams that dealt with fatigue, two that had severe fatigue and two that had moderate fatigue. As luck would have it, both groups were split deadball/modern and AL/NL, so the overall effect on the league stats was minimal, if it had any impact at all in terms of shifting this. The one aside on that is that of the two severely fatigued teams, the modern team won 9 less games than the deadball version (16 wins and 27 wins). If you balanced out just those severely fatigued teams to 21 each, then the W-L totals shift to:

Deadball W: 80.58 · Deadball W%: 0.497
Modern W: 81.42 · Modern W%: 0.502

Showing how really close this was. Essentially, I think this makes it very clear — there is no value difference between deadball or modern pitchers once you account for errors and XBH/HR rates. The run allowance and W/L records the various pitching eras provide for the price are essentially identical.

The base salary seems to really account for these variances exceptionally well in terms of pricing actual sim value.

For myself, I prefer modern pitchers, as I believe it is easier to build offense/defense/ballpark around them, since you have multiple ways to get their full value — where with deadball pitchers, to get full value, you are limited to a very specific group of defenders, which limits your offense/defense/ballpark options.

Full league data: pitching + defense stats

Sorted by group (Deadball / Modern); totals and difference row at bottom. OAV+E and WHIP+E count errors as hits, isolating the true defensive impact that standard pitching lines hide.

Full league data: sorted by owner

Each owner’s two teams shown side-by-side for direct deadball/modern comparison.