Entry order analysis often shows that early entrants to an industry or technical subfield of an industry outperform laggards. Some studies, though, have found that late entrants prevail. This paper tests dual-clock hypotheses of entry order effects on performance, measured both as market share and survival. One entry clock records the entry of all entrants to a new technical subfield within an industry, while a second clock records the entry of industry incumbents. Relative to the appropriate clock, early entrants are predicted to outperform laggards, but when entry is measured on only one clock, the estimated influences may be inaccurate. Error will be particularly likely if a study contains a survivor bias. The study, which finds entry timing trade-offs between market share and survival, is generalizable to cases in which a plausible set of conditions is found.