Presented here are the top 10 runs created tallies for position players from weekend series, May 4-6. Players must appear in the 2012 Baseball America Prospect Handbook.

• With four homers on the season, Blue Jays Triple-A first baseman David Cooper is nearly half way to his total of nine that he hit with Las Vegas last year. All four have been hit in hitter's paradise in Vegas, where he's hitting .411 and slugging .740 (minor league splits). A first baseman with Cooper's feel for contact and gap power can play in the big leagues, but it might have to be with a second-division team or as a pinch-hitter for an NL club (the next Ross Gload?) unless he develops more over-the-fence power.

• Red Sox shortstop prospect Jose Iglesias' recent performance looks even better when you realize he hit just 10 extra-base hits in 101 Triple-A games last year. Boston probably will be happy if simply continues drawing walks like he has for Pawtucket this season. He has 11 in 26 games, giving him a .330 on-base percentage.

• The Rangers have two top prospects in Double-A with no obvious place to play in the Texas infield at this time. Shortstop Jurickson Profar is on a 17-game hitting streak for Frisco, while third baseman Mike Olt is batting .287/.394/.565 with seven homers through 108 at-bats. Never fear: Things can change quickly in baseball—trades happen (such as the 2010 deal that shipped Justin Smoak to Seattle), players switch positions (Olt had dabbled at first base this season), etc.  

• Center fielder Mason Williams took part in the Yankees' offseason strength-training program (BA subscription required) and the early returns in low Class A have been encouraging. He has two homers and has slugged .500 for Charleston through 25 games after hitting three bombs and slugging .468 for short-season Staten Island last summer. To this point, Williams appears to be a step ahead of where Austin Jackson was at the same point in his Yankees career.

• The Diamondbacks landed Paul Goldschmidt in the eighth round of the 2009 draft and followed the next year by taking Adam Eaton in the 19th round. Even if both top out as part-timers in Phoenix, that's some serious value coming from the draft's later rounds. A Miami (Ohio) product, Eaton hasn't yet played his way off center field after earning a quick promotion to Triple-A Reno, where he's batting .385/.442/.526 with eight extra-base hits and five steals in 18 games. No wonder the Diamondbacks felt comfortable trading last year's Reno breakout, Collin Cowgill.

Top Performance By A Prospect-Eligible Player Outside His Team's Top 30

Triple-A Tucson first baseman Matt Clark launched two homers and two doubles at home against Sacramento over the weekend, part of 9-for-13 showing that included two walks and a strikeout. Few Padres farmhands have raw power in equal measures as Clark (he hit 23 homers in Triple-A last year and 28 in Double-A two years ago), but even with Anthony Rizzo out of the picture, he still falls behind Yonder Alonso, Jesus Guzman and Kyle Blanks (who's out for the season) on the organization depth chart.

Rough Stretch

High Class A Lancaster first baseman Telvin Nash of the Astros system went 0-for-9 with six strikeouts and also grounded into a double play during a forgettable weekend.

The Bill James-devised runs created metric (Wikipedia entry explains ’02 version) rewards batters for avoiding outs and reaching base safely (on-base percentage) and for accumulating total bases (slugging percentage), two factors that correlate strongly with run scoring, and for obvious reasons.