Interesting, I'd just prerank my players and let BPA work it's magic. I move players I'd like to have with mid round picks up in rankings like 20-24spots. This year it's Matt Moore,Salvador Perez,Josh Rutledge,Norichika Aoki,Shelby Miller. Those five I'm reacing for but overall I expect will provide greatly on your teams this year. Moore is Ace in making. Perez is the next Piazza. Rutledge will be 2b/SS eligible batting atop Col's lineup. Aoki batting atop Milw's lineup should have 30SBs or more. Miller is Wainwright in the making only with a higher k/9....
So, with that said while I raise those 5 up I'm going to be grading down Catchers/2b/SS and with SPs I'll grade one tier higher to pair with Moore and grade the following tiers lower. Miller probably in the upper mix of that lower tier which he's not even in top 500 on ESPN. so to be in the 160-200 ranking should net me him.
Generally, I pick 1b/3b first in my drafts. These are going to be mashers/RBI types that happen to bat for decent average. But honestly, you should have a good handle on ranking your top 30 and however your pick falls on that rank you should feel happy with the pick no matter the position.
If you're autopicking you will need to rank multiple slot players much higher for flexibility. guys like Prado/Montero/Napoli/Zobrist. This way if you get say OF/Catcher heavy these guys can at least play 1b/2b/3b for you should you miss out with your rankings on landing a 1b/2b/3b of any quality.
Closers, forget them rank them all low enough where you should pick from whats left in your last 2 rounds based on your rankings. so if the last two rounds are pick number 231-250 I'd rank my closers all there 220 on down. Removing the closers alone should move decent bats and pitchers up high enough as rounds go by that you make solid picks.