OK, so I went through the first 5 rounds of the 1997-2000 draft. After looking at all of the data, I came to the conclusion that the sample size was just too small. Here is what I came up with though.
*Note, when I say major contribution for pitchers it was the year drafted + 3 years. Then take the remaining years through 2006 and multiply by 90 innings. If a pitcher qualified, they were a M/C regardless of how good and or bad that player was. For the position players I went with 1000 at bats for college players and 800 at bats for HS players.*
High School pitchers made a MLB debut 36.2% of the time
College pitchers made a MLB debut 42.1% of the time
Only 3.62% of the HS pitchers made a Major Contribution
Only 8.12% of College pitchers made a Major Contribution
High School hitters made a MLB debut 33.5% of the time.
College hitters made a MLB debut 49.1% of the time.
Only 12% of HS hitters were a major contributor.
Only 21% of College hitters were a major contributor.
Hitters By round
Round 1 MC
HS - 20.4%
C - 46.6%
Round 2 MC
HS - 10.3%
C - 23.5%
Round 3 MC
HS - 8.5%
C - 0%
Round 4 MC
HS - 10.7%
C - 15.7%
Round 5 MC
HS - 0%
C - 13%
Draft by position M/C only
First Base
HS - 11.7%
C - 23%
Total - 16.7%
Second Base
HS - 0% (note, only 1 2B drafted)
C - 11.1%
Total - 10%
Third Base
HS - 17.6%
C - 42.8%
Total - 25%
Shortstop
HS - 13.6%
C - 21%
Total - 17%
Outfield
HS -12.7%
C - 26.8%
Total - 17.8%
Catcher
HS - 6.8%
C - 9%
Total - 7.8%
Now like I said, after looking at all the numbers and through the data, I don't think a 4 year stretch is enough data and will probably expand the criteria and go back to 1993 or 1994. With that said, College players seemed to pan out quite a bit more often than High School players. After round 1, college players seem to pan out quite a bit less, but they pan out at consistant rates regardless of the round after 1 they were drafted.
In both the HS and College crop, third basemen were easily the most successful at turning into contributors. Catchers on the flip side were easily the worst at turning into contributors. I am willing to go as far as to say don't waste any top 5 round pick on a catcher who has about an 8% chance of ever being worth while enough to play.