Keep in mind that this is not a traditional top prospect list because it focuses entirely on 2013 contributions. I rank guys according to advanced metrics which, for position players, include batting runs above average, positional adjustment, defense, and a replacement level calculation that scales the total to "Wins Above Replacement" (though the concept of replacement level doesn't really apply to minor leaguers). I use a standard "runs allowed based" WAR formula for pitchers.
(21) Eric Stamets, 21, SS. High A. 2.7 WAR, -8.4 bat, +7.5 glove. .279./334/.373 with 4 HR and 16 SB
For the record, Baseball Prospectus pegs 2013 Stamets' contributions at 5.4 WAR -- double what I have here -- which would rank the second best performance among all Angels' farmhands. The reasons are three-fold: first, BP's "fielding runs above average" calculator is twice as enthusiastic about Stamets' glove than my conservative +7.5 estimate. No doubt, he really is an outstanding defensive shortstop. Second, they credit Stamets with four (corrected) base running runs that I don't include. Lastly, BP is much more aggressive about adjusting offense that occurs in Inland Empire up to Cal League norms. All of the 66ers, including Mike Snyder, Brian Hernandez, Alex Yarbrough, and Zach Borenstein, benefit from BP's sympathetic weighting by a about a full win each (which would, incidentally, make Snyder's performance the 14th or 15th best in the system, and Zach Borenstein, well, wouldn't you like to know!). I get my own +/- runs created number from Fangraphs, which uses a different algorithm, but perhaps I should go back to calculating runs contributed with the bat myself.
Stamets is pretty darn good, and will be a major leaguer, if a marginal one. His glove is good enough to get him to the bigs and ensure him a place on the Halos' forty-man roster through his option years at least, after which he will likely continue finding employment as a slick-fielding shortstop well into his 30's. In order to claim a permanent gig on someone's 25-man, however, he's going to have to improve with the stick. He has little-to-no power, so pitchers will challenge him all the way up the line. I watched him hit against Giants' flamethrower Kyle Crick back in August and Stamets' issues were obvious: he had the presence of mind to line an all-spin-no-break slider up the middle for a hit in his first AB, but swung through 3 straight FB's to K in his second AB. Figuring out good same-sided pitching is his white whale, but if he resolves those issues he's got a shot at becoming a regular. He's got youth on his side.
(22) Brian Hernandez, 24, 3b. High A. 2.7 WAR, +2 bat, +5 glove. .294/.358/.400 with 6 HR and 6 SB
The Halos drafted Hernandez in the 27th round of the 2011 draft out of the UC Irvine. He was meh in his debut, but won the third base spot with Inland Empire in the spring of 2012 before Kaleb Cowart displaced him. He returned to the 66'ers this year, and was a key contributor to the club that eventually won the Cal League championship. His calling card is his glove: he can really pick it at third base. He's not a zero with the stick either, and slotted in nicely as a righty contact bat behind swing for-the-fences Mike Snyder. His gap pop is below average, though his walks have steadily ticked upwards, so he should continue to contribute in the lower minors . Hernandez has Kaleb Cowart -- who is no doubt slated for a return trip to AA -- ahead of him, so will likely return to the California League for the third time in 2014 as a veteran presence on what could be another competitive Inland Empire club, assuming some of the college arms from last year's draft step up.