Rank is a curve, not a ladder
The gap between a system's number one prospect and its number five is enormous. The gap between number twelve and number twenty is close to nothing. Prospect value decays roughly exponentially with rank, which is why lists flatten into noise past the top ten of an organization.
The same is true nationally. A consensus top-ten prospect is a franchise asset. A player ranked in the eighties on a top-100 list is a good bet who still busts more often than not.
Age relative to level is the single best filter
A 20-year-old holding his own in Double-A is a far better bet than a 24-year-old dominating High-A. The average age at each level is roughly 18 in complex ball, 20 in Low-A, 21 in High-A, 22.5 in Double-A, and 24 in Triple-A.
When you see a strong stat line, check the age gap before you get excited. Two years young for the level with average production usually beats age-appropriate production with great numbers.
Double-A is the real test
The biggest talent jump in the minors is from High-A to Double-A: that is where advanced breaking balls and real command arrive. Triple-A is closer to a staging area, with a mix of prospects and veteran depth.
A hitter who keeps his strikeout rate stable and his walk rate intact through the Double-A jump is telling you something meaningful. Complex-league and Low-A numbers, by contrast, should be treated as background noise attached to a scouting report.
ETA changes present value
Two prospects with identical talent are not worth the same if one arrives next spring and the other arrives in 2029. Proximity reduces risk, delivers cheap production sooner, and matters more to a contending club than to a rebuilding one.
This is why sellers and buyers often prefer different profiles in the same trade. A rebuilding team may happily take the more distant, higher-variance teenager.
Depth versus impact
Systems get ranked on both, but they are traded very differently. Impact talent — the top handful — buys stars. Depth buys role players and absorbs the cost of bad luck. A system with fifteen interesting arms and no star is deep and unimpressive.
In Diamond GM you can trade any player in an organization, not just the ranked names, which is the honest version of how deals get built: the fourth piece in a real trade is almost always an unranked Double-A arm the acquiring team's pro scouts happen to like.
Pitching attrition is real
Minor league pitchers get hurt at a rate that should permanently temper enthusiasm. Value them accordingly: discount distant arms harder than distant bats, treat any pitcher who has already had a major elbow surgery as materially riskier, and prefer the prospect who has already shown he can hold a starter's workload.