It's actually not to hard to make a card, per se, as long is you either use actual baseball cards or print off a picture of your players off the internet.
The problem is the formula for making the cards and their charts, because without those, you got nothing.
Now, this is based off memory of a formula created by a user on Showdowncards.com's forums before they killed it. I do not know the user's name, but whoever you are out there, thank you. This is for the 2000 and 2001 sets, since I like them best.
OBP of .470+ = 11 (yes, there are players this good...)
OBP of .390-.469 = 10
OBP of .360-.389 = 9
OBP of .340-.359 = 8
OBP of .315-.339 = 7
OBP of .290-.314 = 6
OBP of .260-.280 = 5
OBP of .240-.259 = 4
OBP <.239 = 3 (yes, there are players this bad...)
These stats can easily be found at websites like Baseball-Reference or Fangraphs, so you don't have to try and calculate them by hand.
Now, the number of outs a batter has on his chart is up to you; if they are on the lower end of the scale, say, with a .342 OBP, they can get 5 outs. Likewise, if they're on the high end, say, with a .359 OBP, I'd give them 3 outs.
Walk (BB) Results:
Take the Batter's Average (BA) and subtract it from the OBP. For every twenty, they get one BB result.
So, for example, Mark Reynolds of the Baltimore Orioles had a .221 BA and a .323 OBP.
323-221 = 102, so he'll get 5 BB results.
You will have to round up or down to the nearest 20.
Triple (3B) results:
If they got 6-7 triples in a season, they get one 3B result. Double that, get 2 3B results, etc.
Doubles (2B) and Home Run (HR) results:
Take the number of doubles or home runs the batter has hit, divide by the b=number of at-bats (AB), then multiply by 600. For every ten, they get one 2B or HR result.
So, using Mark Reynolds again, he had 27 doubles in 534 at bats.
(27/534) x 600 = 30.34, so he'd get 3 double results.
This is up to you. They steal more than a dozen bases? Give 'em one Single+ result. They steal a lot of bases? Maybe more like three or more.
Whatever space you have left between BB and Single+ results are just plain old Singles.
If the player has an On-Base of 8 or higher, you just use the results from above. If they have a lower On-Base than that, they get an adjustment.
On-Base 7: +1 for Doubles and Home Runs
On-Base 6: +1/2 for Doubles and Home Runs, maybe +1 for Triples
On-Base 5: Provided the actually hit some, +2 for doubles and Home runs
On-Base 4 & 3: You get the idea.
Now, this is part art, part science. Don't let that get you down.
Did they steal a lot of bases? A
A Few? B
Were they tortoises? C
This is mostly subjective as well, except for catchers. Remember, there are no defenders with a negative, if they are that bad it stops at +0.
For catchers, we only need their caught stealing percentage (CS%), and divide by 5. For each 5 (rounded), they get +1.
So a catcher who only catches 25% of his base stealers gets a 'C+5', while a catcher who gets 44% of his base stealers gets a 'C+9'
First baseman have a default +0, so if they actually play good defense they get a +1 (Maximum)
Second baseman default at +2 (for an average defender), up or down depending on how good they are, minimum of +0, maximum of +5
Shortstops default at +2/3, ranging from +0 to +6
Third baseman default at +1/2, range from +0 to +3
Outfielders default at +1, LR types range from +0 to +2 and CF types from +0 to +3
This is the point you've been waiting for, and...
I don't know it. I honestly compare them with similar players and adjust the cost accordingly.
Well, I hope somebody can use that, and I will approach pitchers later.