Catcher
Having a catcher with 99 Arm Strength and 99 Arm Accuracy is a huge weapon when defending against all of the over-aggressive base runners that you'll encounter online in Diamond Dynasty. There aren't any catchers in MLB 15 with contact and power ratings in the 90s, either, so you'll benefit on offense as well.
Center Fielder
Unless you're lucky enough to own Mike Trout, you won't find any speedy center fielders in MLB 15 who can swing the bat just as well as they can snag fly balls. Having a fast outfield in Diamond Dynasty is often the difference between making a running catch in stride and allowing lots of doubles and triples to bounce through the gaps and off the walls.
Shortstop
Aside from Ernie Banks and Troy Tulowitzki, most shortstops in MLB 15 are defensive specialists. If you can't afford one of those all-around studs, and you want a shortstop who can shutdown infield singles without being a free out at the bottom of your batting order, then you might want to move your created player to short.
Long Reliever
While there are plenty of superb closers, set-up men, and middle relievers to pick from in Diamond Dynasty, skilled long relievers with high stamina and excellent pitching attributes are as rare as a Sean Doolittle curveball. Plus, if one of the weaker pitchers in your rotation ever gets selected to start the game you can simply warm up your created player as soon as the match begins. Then you can bring him out of the bullpen at full readiness by the second inning.
This year, your created player's attributes will only increase whenever you sacrifice some of the cards in your collection and "feed" them directly to your CAP. His attributes will grow based on the skills that you feed to him. Here are some cheap cards that you can grab from the marketplace to sculpt a well-rounded superstar:
Hitting
Mark Trumbo, RF (Arizona) -- 93 power versus lefties
Pedro Alvarez, 1B (Pittsburgh) -- 87 power versus righties
Kevin Frandsen, 3B (Washington) -- 93 contact versus lefties, 92 vision
Adam Lind, 1B (Milwaukee) -- 91 contact versus righties, 88 clutch, 87 durability
Stealing
Jarrod Dyson, RF (Kansas City) -- 99 speed, 99 stealing, 99 baserunning aggressiveness, 93 drag bunt, 92 reaction, 84 fielding
Defense
Jason Motte, RP (Cubs) -- 99 arm strength, 89 velocity
Brendan Ryan, SS (Yankees) -- 93 fielding, 84 reaction, 82 arm strength
Jarrod Saltalamacchia, C (Miami) -- 82 blocking, 81 fielding, 83 arm strength
Pitching
Antonio Bastardo, RP (Pittsburgh) -- 95 break, 97 K/9, 88 H/9,
Brandon League, RP (Los Angeles) -- 96 velocity, 93 arm strength
Matt Belisle, RP (St. Louis) -- 93 control
Jason Vargas, SP (Kansas City) -- 91 stamina