OK, the research is in and both unders are substantial favorites in my opinion. Its pretty clear that the SM just looked up last year and set the totals based on that. 11 home runs have won the final round only twice in the last 10 years (and never more than 11). Additionally only 27/140 individual rounds have gone over 10.5. Conclusion: under is a massive favorite.
Average second round total is 27.2 with under 30.5 going 7-3. A possible cautionary factor is that Chase Field is #5 in HRs this year. However it was only #12 last year and #14 in 2009, and just a smidge above average both years, so I don't think it is really that HR friendly. Conclusion: Under is a small-medium favorite.
I have included the first round averages for each year, although there doesn't really seem to be any correlation between rounds. That tells me there is a huge amount of luck involved here. (Not: both the 8.88 averages were highly skewed by one gut hitting into the upper 20s. Both freak occurrences, since the 3rd highest round total in the last 10 years is 17.)
2010
30 in r2
11 last round winner
4/14 over 10.5
6.13 1st rd avg
2009
25 in r2
6 last round winner
2/14 over 10.5
5.75 1st rd avg
2008
26 in r2 (1 player didn't use all outs)
5 last round winner
1/14 over 10.5
8.88 1st rd avg
2007
38 in r2
3 last round winner
1/14 over 10.5
3.88 1st rd avg
2006
21 in r2
5 last round winner
1/14 over 10.5
7.13 1st rd avg
2005
21 in r2
11 last round winner
4/14 over 10.5
8.88 1st rd avg
2004
33 in r2
5 last round winner
1/14 over 10.5
5.75 1st rd avg
2003
35 in r2
9 last round winner
3/14 over 10.5
4.25 1st rd avg
2002
21 in r2
7 last round winner
2/14 over 10.5
5.34 1st rd avg
2001
22 in r2
6 last round winner
1/14 over 10.5
4.5 1st rd avg
P.S. Every year except for last year there has been at least one tie in the first round, usually 2 or 3, so "or tie" is worth quite a bit.
Average second round total is 27.2 with under 30.5 going 7-3. A possible cautionary factor is that Chase Field is #5 in HRs this year. However it was only #12 last year and #14 in 2009, and just a smidge above average both years, so I don't think it is really that HR friendly. Conclusion: Under is a small-medium favorite.
I have included the first round averages for each year, although there doesn't really seem to be any correlation between rounds. That tells me there is a huge amount of luck involved here. (Not: both the 8.88 averages were highly skewed by one gut hitting into the upper 20s. Both freak occurrences, since the 3rd highest round total in the last 10 years is 17.)
2010
30 in r2
11 last round winner
4/14 over 10.5
6.13 1st rd avg
2009
25 in r2
6 last round winner
2/14 over 10.5
5.75 1st rd avg
2008
26 in r2 (1 player didn't use all outs)
5 last round winner
1/14 over 10.5
8.88 1st rd avg
2007
38 in r2
3 last round winner
1/14 over 10.5
3.88 1st rd avg
2006
21 in r2
5 last round winner
1/14 over 10.5
7.13 1st rd avg
2005
21 in r2
11 last round winner
4/14 over 10.5
8.88 1st rd avg
2004
33 in r2
5 last round winner
1/14 over 10.5
5.75 1st rd avg
2003
35 in r2
9 last round winner
3/14 over 10.5
4.25 1st rd avg
2002
21 in r2
7 last round winner
2/14 over 10.5
5.34 1st rd avg
2001
22 in r2
6 last round winner
1/14 over 10.5
4.5 1st rd avg
P.S. Every year except for last year there has been at least one tie in the first round, usually 2 or 3, so "or tie" is worth quite a bit.