Some guys swing at everything because they can't figure out what pitches are coming out of the hand (Austin Hays). Other guys swing at everything because they can hit everything (Miguel Tejada). I'd put Mountcastle in the latter category based on what I saw from him this season.
Looking only at a low walk rate is indicative but doesn't tell you everything. Gotta see the actual approach to know if the low walks are because of bad plate discipline or because of justifiably aggressive approach. If its because of bad plate discipline in the minors, that'll likely get worse as they climb the ladder and the overall offensive production will plummet. If it's because of an aggressive approach with a strong hit tool, then the overall production should be more sustainable. A low walk rate will always put a lower ceiling on a guy than someone who can draw more walks while maintaining the ISO and AVG. OBP is very important and drives run scoring. But you can still be a very good to great hitter without walking a lot, it's just more difficult.
Agree completely.
The armchair scouts that like to correlate stats to characteristics miss this one a lot. Some guys are just very aggressive and feel like they can hit everything so they swing more. It’s not that they couldn’t draw walks if they wanted to, but most of them feel like the minors is where you swing away and get even better at it, not take your walks and help the team.
I’ve known a bunch of minor league guys and the ones that are legit ML prospects view improving personally more important than team wins in the minors so it plays out like this sometimes. Some have been coming around the past few years and realize displaying the ability to take walks is a positive, but many of them still view walks as a negative to the pitcher, not a positive to the batter.