So, in general, I would say I value ceiling more than SoxProspects does. They tend to rate AAAA players a lot higher than I do because I would rather dream on upside over guys who can maaaaybe be replacement level players & don't really have a clear path to being better than that.
In Walter's defense, '22 Walter seemed like a player with decent upside. In 50 AA innings over 9 starts, he had a 2.88 ERA (2.26 xFIP), 0.78 WHIP, 12.2 k/9, 0.5 bb/9...kind of absurd. The downside was that it was his age 25 season & he turned 26 in September of that year. He pitched 7.2 innings over 2 starts in AAA & it didn't go well (8.22 ERA, 4.7 bb/9), but tiny sample size.
I might rate Walter higher than where I currently have him (I have him 61, SP has him 32) if I was invested in the Red Sox MiLB in '22 the way I started to be partway through this year, buuuut I wasn't, so he doesn't get as much credit for his dominant AA season, & I judge him more for his ~ok AAA season & pretty bad MLB season.
AAA - 94 IP, 4.60 ERA (4.60 xFIP), 1.43 WHIP, 8.4 k/9, 3.4 bb/9
MLB - 23 IP, 6.28 ERA (5.28 xFIP), 1.70 WHIP, 6.3 k/9, 2.7 bb/9
In MLB, Walter's 91.3 mph fastball was in the 13th percentile & his k-rate & whiff % would have been much lower than that if he qualified.
His sweeper & cutter were fairly effective, but his sinker & changeup got rocked. He seemed pretty useful against lefties (except the .467 BABIP), but was pretty awful against righties (5.2 k/9, 3.3 bb/9, 5.73 xFIP), & unless he can figure out how to get righties out, there isn't much of a role for him in modern baseball. He kind of profiles like a 27 y/o poor man's Bernardino right now, which isn't a great profile. So I would happily move him for value unless there is some sort of known injury he was pitching through or something.
On the flip side...he did seem to figure something out in Worcester along the way. Perhaps related to his time in MLB? But is becoming a good AAA pitcher the goal?
Prior to first promotion to Red Sox (4/1/23 to 6/17/23):
13 Games
12 GS
61.2 IP
43 ER
76 hits
26 walks
64 strikeouts
6.28 ERA, 1.65 WHIP, 3.8 bb/9, 9.3 k/9
After first promotion to Red Sox (6/30/23 to 9/22/23):
8 Games
6 GS
32.1 IP
5 ER
23 hits
9 walks
24 strikeouts
1.39 ERA, 0.99 WHIP, 2.5 bb/9, 6.7 k/9
My guess is he realized that he had enough movement on his stuff to be able to pitch to contact & still get AAA hitters out rather than trying to blow it past them. It does not seem to work the same against MLB hitters, though.
So yeah...that's why I have him 61...I don't see him ever being an MLB starting pitcher you want in your rotation, & he only has limited usefulness currently as a lefty specialist. & he is already 27.