No need to overthink the analogy. Pro gamblers choose their games while VM developers don’t. The analogy works for those games the gambler did happen to play.

No need to overthink the analogy. Pro gamblers choose their games while VM developers don’t. The analogy works for those games the gambler did happen to play. Let me give you more concrete data. On JSC we did tune for microbenchmarks in addition to macrobenchmarks. But the microbenchmarks would show pathologies not seen in the macrobenchmarks, those pathologies were unpredictable (you breathe on the VM and the behavior changes), and anyway real programs were more like macrobenchmarks than microbenchmarks. So - based on experience we switched to using the microbenchmarks only if they reliably reproduced behavior that we first observed in a macrobenchmarks. Got a macrobenchmark regression? See if any microbenchmarks also regressed in hopes of finding something easier to study. Otherwise the microbenchmarks were just whack-a-mole - if you focus on one of them you end up making changes that hurt real stuff. Sort of like if a gambler focused too much on one game, they’d end up losing in the average.