I don't wholly subscribe to any computer/analytical rating system, but FPI is one of the better ones. It takes into account record, strength of schedule, unit efficiencies and game control.
Updated after the quarterfinals, FPI has Ohio State 1, Texas 2, Notre Dame 3. There is a substantial gap between those three and #4 Alabama (have questions about that one).
Comparing playoff opponents, Georgia is 6, Penn State is 7 and Indiana is 10.
Comparing offensive efficiencies, Indiana is 4, Penn State is 8 and Georgia is 12.
Comparing defensive efficiencies, Penn State is 6, Georgia is 14 and Indiana is 21.
Updated after the quarterfinals, FPI has Ohio State 1, Texas 2, Notre Dame 3. There is a substantial gap between those three and #4 Alabama (have questions about that one).
Comparing playoff opponents, Georgia is 6, Penn State is 7 and Indiana is 10.
Comparing offensive efficiencies, Indiana is 4, Penn State is 8 and Georgia is 12.
Comparing defensive efficiencies, Penn State is 6, Georgia is 14 and Indiana is 21.