Original Reddit post

The common wisdom is that Claude gets sloppier as the context fills up, so you should compact or hand off early. I wanted to know whether that’s true in my own work, so I mined my session logs: 52 sessions, 9,096 turns, 19 Sep – 9 Oct. For each turn I recorded how full the context was and whether Claude broke one of the rules it’s given. Fill Turns Violations 0-20% 1,342 8.7% 20-40% 2,783 6.9% 40-60% 1,700 6.5% 60-80% 1,995 5.4% 80-100% 1,276 5.5% What surprised me:

  • No rise as it fills. If anything it falls. The slope is flat (odds ratio 1.01 per +10 points of fill), and comparing turns within the same session shows no difference (p = 0.43).
  • What predicts mistakes is how early in the session a turn is, not how full the context is. Turns 1–15 are the worst, at 11–14%. It looks like warm-up, not decay.
  • I also checked how often I push back on Claude. That’s U-shaped: high early, high late, low in the middle. But most of the “pushback” was me asking short questions, not correcting it. Real disagreement (“no”, “wrong”, “stop”) is about 3–4% early, ~1% mid-session and 5% late. Within-session comparisons don’t make that significant either (p = 0.30). Caveats, because they matter: One person, one workflow, so not a controlled experiment. My setup re-injects a short list of rules on every turn via a hook. So this measures “with that mitigation”, not raw attention. It may simply be that the rules never get a chance to sink into the middle. Most “violations” are one rule (the reply must start with a timestamp), because it’s the one that’s trivially checkable. Rules that need judgement aren’t counted at all. So my takeaway isn’t “context rot is a myth”. It’s that, for rules repeated every turn, I couldn’t see it, and I’m not compacting early on that basis. Next I’m running a controlled probe: the same recall and instruction questions at 0/20/40/60/80% fill, several repeats each. Has anyone measured this on their own sessions? And does compacting early actually make a difference you can see, or is it just habit? submitted by /u/shaven12

Originally posted by u/shaven12 on r/ClaudeCode