MLB Draft Talk: High Schoolers or College Players?

College and High School baseball is about to start. So even though we are several months away from the baseball draft, teams are already sending out scouts across the nation to look at prospects. So yeah, its time to start thinking about the draft. Here, I wanted to see which players are usually better choices, high school players or college players.
Since 1965:
1st overall picks (rated according to WAR):
The top 6 Players are out of high school. Only 3 out of top 10 were out of college. 19.5 WAR was "average" for each player selected first overall. Excluding 2008, 2010-2011, the 3 players drafted first overall that did not make the majors were all out of high school. Out of the 8 with negative WAR, 4 were out of college, 4 were out of high school. Out of the 27 (that's excluding the 2008, and 2010-2011 picks) "under-average" 1st overall picks, 14 were out of high school, so about split.

2nd overall
4 out of the best 5 went to college. Excluding the 2010-2011 picks, 13 players either had negative WARs or didn't play in the Majors. 8 of them were drafted straight out of high school. The 2nd overall pick averaged just 12.4 WAR. That is a big drop off from the 1st overall pick, so in 2012 there will be a big expected difference from the player the Astros get opposed to the one the Twins get at number 2 overall.

In the first round of the "Moneyball" draft of 2002, the top 4 players all came out of high school. Only 3 of the top 10 came out of college, and 2 of them were drafted by the Athletics. Only 5 out of the 14 that never made the MLB were drafted straight out of high school. Every single player, except 1, that reached the Majors and had a 0 or negative WAR was out of college. In the 2003 draft, 3 of the top 5 were out of college, while 11 of the 18 players that didn't make the Majors or had negative WARs were out of high school. However, in 2004-2006, 4 of the top 5 were college players each year.

When we look at all the pitchers drafted in the first round since '65, 51% of high school pitchers made the Majors. Those players averaged a 5.9 WAR. When you add Junior College players into this list, the same amount make the Majors, but the average WAR goes up to 6.1. When College players are added, we go up to 58% of players making the Majors. However, the average WAR for those players is 5.8. In round 2, 42% of all draftees make the Majors, and those average a 5.2 WAR. High schoolers in the 2nd round made the Majors 36% of the time, but had an average WAR of 6. Junior College players reached the Majors just 28% of the time and those players had a WAR of just 4.6 on average. So it seems that high school players have much higher ceilings, while college players are less risky, but provide less reward (and Junior College players are hit and miss).