Up through his age 27 season (2000-01; he would miss the entirety of the 2001-02 season), Forsberg played in 86% of his team's games, compared to 91% for MacKinnon up through the end of last season (his age 26 season). MacKinnon played in 638 regular season games, compared to 466 for Forsberg (a function of (i) MacKinnon entering the league when he was 18, compared to 21 for Forsberg; and (ii) the higher number of missed Forsberg games. If you're looking to start a franchise, not knowing how the remainder of MacKinnon's career will play out, you have to ask yourself whether Forsberg's on-ice contributions make up for the lower number of games vis-a-vis MacKinnon. I'm not sure if they do, honestly. The big edge that Forsberg usually has - playoff performance - doesn't really exist (or if it does exist, its not a clear edge) versus MacKinnon. Forsberg's certainly the better per-game player and the equation changes dramatically if Forsberg comes over to North America earlier, but measured right now MacKinnon has played a little over 2 seasons of more of (mostly quality) games than Forsberg did at a comparable age.