Silva's staffs put up 3.50 and 3.12 ERAs the last two seasons. Pitching has not been a chronic weakness before.
Do you know what our ERA was during our top 10 rankings?
I'll preface my numbers by saying I'm not going to argue that Silva is better than Childress, I don't necessarily believe that, and quality of opposition is a key factor as caveman pointed out, but I have some of the numbers in a spreadsheet because I get bored sometimes so I'll post them (ERA, K-to-BB ratio to keep it simple).
2005 was a statistical outlier so I didn't bother keeping their numbers, I remember the 2.68 ERA, this is the best pitching staff we've ever had and may ever have. A good mix of upperclassmen (Duensing, Kroenke) and new guys (Chamberlain, Dorn) that ate up innings for a good bullpen (Watson, Jensen, Bohanon et al).
2000: 3.14 ERA, nearly a 3-1 K-BB ratio (484 to 167), that was also a deep and talented staff.
2001: 4.41 ERA, an insane 503 strikeouts to 187 walks.
2002: 3.66 ERA, 478 strike outs to 185 walks.
One non-top 10 year of note: 1999's Big 12 tournament champions had a 5.55 ERA with 438 Ks to 191 BBs.
Silva's numbers from 2012 through 2015 total: 3.92 ERA with 1381 strike outs to 748 walks (345-187 per year average, about a 2-1 ratio, he preaches pitching to contact so I doubt the strike out totals will ever approach 450, much less 500, and that's OK.) Once again, the difference in conference opposition is worth noting, but I think the overall performance has been adequate