Just to amplify what others have said: the sum of all three of points on Francis' checklist is greater than its parts.
1) chance to play: 100%. Study year to year stats. See who's graduating. See who's waiting in the wings. Both Smokesons looked for and were fortunate to find mutual attraction with D3 schools where at least one starting outfielder graduated in May before they joined the team in August. What I didn't anticipate for son #1 was that one of the other OF recruits would be a power hitter, which #1 is definitely not. I also didn't expect him to compete with either of the heir apparent OFs: one led the team in hitting the year before, and the other had the most experience of any of the non-starters. So what happens is the other frosh hits with power and initially takes the third spot during fall ball and preseason and has started every game since. The OF leading the team in hitting did it again. But the guy who expected to start after spot playing for three years had a brutal fall and preseason slump, lost his spot, and left the team after its Florida trip.
2. Successful program: 23.7%: All the D3 schools Smokesons looked at had winning records and recent playoff history, if not regionals, then at least conference tournaments. #1 eventually played in a regional and said it was awesome being there. #2's team had been the D3 CWS the year before he was recruited. The relative strength of each team mattered, but if a HA D1 (Patriot or Ivy) had come calling then records wouldn't have mattered to either of them. At all.
3. Play for a coach you admire: 37% but I would change admire to tolerate, and if you end up admiring the guy, then that's a bonus. Research this as much as possible, though, because you don't want a guy who promises your kid the moon, and then disappears as soon as your kid gets in the door. Research is also important because someone, somewhere who thinks they weren't treated fairly by the coach may want to do a hatchet job on them. I've seen it on this site and I've heard in the stands at showcases. Don't settle for just one opinion, good or bad. Biggest priorities about the coach for me as a parent was this: Is the dude FAIR? Is he HONEST?
So total percentage of those three: 160.7 %. Get that and you'll have a winner.
Smokeson #3 ('22) is heading into the recruiting gauntlet. He's a pitcher, so maybe his percentages will line up differently, but I already know they're gonna add up to more than 100% and the process will be much different for him. He'll either have the velo and control he needs, or he won't. If he doesn't then there won't be any factors at all, let alone 3.