We’re talking about a couple different things here - Nic is talking about the build we run every time we merge to CmdStan master that tests that results haven’t changed much. Sebastian is talking about the relative performance tests that run and comment on github PRs. The results from that are not obviously interpretable in the current format mostly because it’s not clear how they’re computed, but we can do the stuff above in Sebastian’s original pose and using Steve’s 1 - new / old suggestion with the text “% slower/faster” or whatever next to it to try to help - and probably just print the formula for good measure, too. Then that will get included on the pull request and be easier to interpret for newcomers.