Interesting Perspective here from Ritz on summary of training leading into his marathon starts:
https://running.pocketoutdoormedia.com/marathon-taper-trouble-ritz_176840
Debut Marathon NYC 2006
Training: 100% healthy, no problems.
Result: My slowest marathon in 2:14:01. 11th place.
Olympic Trials Marathon 2007
Training: Significant disruptions with Anemia/Peroneal Tendon split tear five weeks out.
Result: 2:11:07. 2nd place. Made the Olympic Team.
Beijing Olympic Marathon 2008
Training: Injured all spring with stress fracture, but 12 solid weeks of training.
Result: 2:11:59. 9th place.
London Marathon 2009
Training: Barely made the line, injured achilles three weeks out and very disrupted taper.
Result: 2:10:00. 11th place.
NYC Marathon 2010
Training: Good solid block for last twelve weeks.
Result: 2:12:35. 8th place.
Olympic Trials Marathon 2012
Training: Injured most of the previous year but five good healthy months.
Result: 2:09:55. 4th place.
Chicago Marathon 2012
Training: Healthiest year I ever had. Except, with 10 days to go I developed the start of a stress reaction in my foot. I ran the whole race with a hole cut out of the sole under my 3rd metatarsal.
Result: PR of 2:07:47. 9th place.
Chicago Marathon 2013
Training: A very healthy year until the last 10 weeks. Very bad plantar fasciitis. Also strained posterior tibial tendon in my ankle 2.5 weeks out. Almost didn’t make the line.
Result: 2:09:45, 5th place.
Boston Marathon 2015
Training: Injured much of the year before. Three months of solid training but injured cuboid bone in my foot four weeks out. Took almost a week off, almost pulled out.
Result: 2:11:20, 7th place.
Olympic Trials Marathon 2016
Training: Great training leading up to the race. 100% healthy. Then three days before the race strained a back muscle, significant pain running.
Result: Dropped out at 20 miles with leg cramping.
New York City marathon 2016
Training: Very good training for much of the year. The last two months were plagued with bad plantar fasciitis. Almost didn’t make the start line.
Result: Ruptured plantar fascia at mile 19 and dropped out.