The sound track from the Fleet Feet program I pace for is, use a half 2 to 4 weeks before the full as a training run, and run it at MP. I'm not sure I know anyone who has actually done that.

Fleet Feet is pumping SummerFest (12K with hills) on 9/3 as a tune up for Rochester (half/full marathon) on 9/18. I'm not running SummerFest this year, I'm running Oak Tree Half on 9/4 instead. My training plan (which I am not rigorously following) calls for 60 minutes easy on 9/3 and has a big blank spot on 9/4. Then 9/5 says 30 minutes easy plus 4 strides. Instead of that, I'm thinking to take a rest day on 9/3 (maybe volunteer for Summerfest), run Oak Tree as a race but not an A race, and if I feel beat up omit the strides on Monday or even take Monday as a rest day. After that, do the taper as per the plan all the way to Rochester.

If Rochester were my *first* marathon, I'd be inclined to be more cautious and try to run Oak Tree at MP. But Rochester is my 3rd marathon, Oak Tree will be my 11th half, and I have multiple goals. In addition to supporting my training for Rochester, Oak Tree is a Rochester Runner of the Year race. I'd like to run it fast enough to win my age group, and I don't know for sure who else will show up.

I'm thinking you might be contemplating the Rochester Half as a tuneup for the Wineglass Marathon? A lot of local runners do that, and I think they mostly run the Rochester Half as a race but not a major target race. Running it as a training run (MP, or down the river trail at MP -10 seconds and up the Thomas Ave hill at MP +10 seconds, or 90 minutes easy and the remainder at MP, whatever) would be a more conservative approach focused on the marathon. Another option would be to hang with one of the pacers at Rochester; if you pick 1:45 (8 minutes per mile), tell Jim that Kevin sent you. Then ask Jim when he thinks you should leave him in the dust and accelerate toward the finish line, given that the full marathon is more important to you than the half. He'll give you an answer that takes into account the terrain of the Rochester Half course.

My plan calls for a race both four weeks and two weeks out. At four weeks, the max distance (on a Saturday) is HM distance but at MP. Note that my schedule then calls for a 17 mile run the next day after the race with Monday as the rest day. Then two weeks out it calls for a 10K Saturday race (also at MP), followed by a 16 mile run.

The key is distance races at MP, not what you can do at the race distance. The trick is whether you can pace yourself under race conditions. IMO that is the real training you are doing in those races, not how fast you can run at the shorter distance. Again, this upcoming marathon is my 9th and I've done 9 HM.

Just for reference, in April I ran a 10K race on 4/2, ran a 5K on 4/9, and then ran a marathon on 4/10. Although I didn't run at the max speed in any of those races, I PR'd both the 10K and 5K and then easily cruised through the marathon with a negative split and a marathon where my last 10K was a story of getting faster rather than slower.