Slitherine

Hi all,
I'm working on a deployment-optimization tool for myself and trying to reproduce exactly what the combat log shows (with setany randomness 0). I've nailed down the kill formula but I'm stuck on a tiny discrepancy in suppression that I can't explain, even on the simplest possible case.

Setup: a single Pz IIIB shoots once at a full T-26. The log says:
Base Number of Shots: 1
Effective Accuracy: 50%
Deflect/Suppress/Kill chances: 30% / 20% / 50%
Prediction: 0.250000 killed, 0.104808 suppressed

The kill prediction matches what I expect: 0.50 (accuracy) × 0.50 (kill chance) = 0.25. Clean.

For suppression, my reasoning is the same: 0.50 × 0.20 = 0.10. So I'd expect exactly 0.100000. But the log gives 0.104808 — a small but very real and reproducible 5‰ excess.

Where does that 0.0048 come from? It's too large to be a rounding artifact (the log displays 6 decimals deliberately) and too small to come from any "panic bonus per kill" mechanism I can think of (a single shot produces at most 1 kill, with 25% probability — and any naive multiplication doesn't land on 0.0048 either).

Anyone here who has investigated the suppression formula and could shed some light on this? Even a hint about the general shape of the calculation would unblock me massively.

Thanks!

Update: I've narrowed down the suppression formula and found something curious that goes beyond the original question.
Same setup (Wehrmacht infantry attacking a Soviet Regular squad in open terrain, setany randomness 0, setany weather clear). I held the defender at HP=5 and varied the attacker's HP from 13 to 16. Combat log predictions for suppression:

13 attacker HP : 0.815 suppressed
14 attacker HP : 0.541 suppressed
15 attacker HP : 0.568 suppressed
16 attacker HP : 0.594 suppressed

Going from 13 to 14 shots, suppression drops by 33%, then slowly recovers as more shots are added. This non-monotonic behavior is hard to explain with a continuous probabilistic formula — adding shots should never reduce suppression, at worst the extra shots have zero effect.

Possible explanations I can think of :

There's a threshold-based branch in the suppression code that activates above some E[K]/HP ratio, producing a discontinuity in this regime
There's an unintended side-effect in the formula at near-saturation
This is intended behavior modeling some tactical concept I'm not seeing

Anyone has insight into how the suppression formula handles near-saturation cases? Happy to provide more datapoints. Saves available on request.