Using TrainingPeaks I have raced short course well off of 0 tsb and trending up for ‘b’ type races but do better on 10ish. Long course I find +20 tsb.

One thing with all of it and I find vital is you MUST keep up some form of intensity. In taper my legs are sometimes like lead like I have lost all my fitness. I huff and puff through easy sections and intensity intervals feel hard as Hell. I feel like utter trash and fat. All workouts become a chore in taper time bit m ntally and physically.
All that means is things are going swimmingly! It comes together on race day- the hunger kicks in and your left fresh to kick some ass.
However if I don’t have any intensity in that week I have zero power for the race.

I don't even bother with a TSB score, because mine are always all over the place and have little correlation to how I actually feel. I've felt brilliant at -20 and +20 and everything in between.

Instead, I'll make sure to get a decent ride in the day before, or even the morning before if a later race, with a couple of efforts above threshold. The worse I feel, the longer/harder I'll generally go.

Too rested always feels worse than too tired, though sometimes you can go really well even though it feels hard. I always prefer not feeling too rested, though (aerobically just feels like there's nothing there). More times you do it, the more you can fine tune it.

Rather than share another personal anecdote, here are a couple tips:

1. The shorter the race/the higher the intensity, the more important it is to be fresh (i.e., TSB equal or greater than +10). Conversely, the longer the race the more careful you need to be to avoid resting too much/too long (and also the smaller the benefit of tapering in the first place);

2. A good way of dialing in your personal use of the PMC approach is to retrospectively apply it to one or more earlier races where things went well, then try to replicate that pattern going forward.

The performance itself predicts performance.

That's a big call. So my tapering for IM Cairns on Sunday reaps me small benefit. I think every coach out there would have to rethink their methodology based on your misguided logic.

Just stating facts. Even the most well-designed and -executed taper only improves endurance performance by a few percent.

Of course, I think many experienced athletes already know this, which is why people tend to train right up to, e.g., a stage race, then lighten the load and eat plenty of carbs only during the last few days. Swimmers, OTOH, frequently taper for 2+ weeks prior to their (much shorter) events.

Note that the extent to which the exercise modality causes muscle damage also seems to be important, e.g., runners and weight lifters appear to benefit from tapering longer vs. cyclists.

What about overcoming fatigue? The 30 hour weeks I did leading in and I was in pieces and taper has been closer to two weeks since the last volume session. Mentally and physically I will have needed every one of those days. The last post was too generic then to be a fact.

Personally I don't use Training Peaks but the shorter the race I feel better carrying a little fatigue in. As the intensity is higher I just feel I can go deeper with that slight fatigue feeling. With Ironman I want to be totally fresh mentally and physically because it is a very long day and I want everything in reserve. I ran into the bf of a pro girl racing Challenge 70.3 Slovakia yesterday and she told him Sanders was smashing himself doing 200's in the pool the day before and everyone on the pool deck was thinking and his gf was saying wtf are you doing? He didn't have a great swim but was that due to fatigue or, wetsuit or other factors I guess we won't know but he had a great race.

If you can watch the finish line interviews of Kienle and Sanders are gold.

It might be generic advice, but for sure the top athletes in races from 2 minutes to 24 hours are following that advice.

If you're mentally and physically smashed to pieces for over two weeks after a block, you probably weren't ready for the training load you did.

When you are training for an Ironman that is the idea. Be close to breaking but don't break as the race gets closer. I didn't break but you think you aren't far from it as a good coach should take you. I was ready and always the same, I know what is coming. Have you ever tapered for an Ironman? It is almost as much mental as physical in my opinion and no I am not in pieces for two weeks but I feel I need that period to have my best race.

https://www.active.com/triathlon/articles/countdown-to-an-ironman-dave-scott-s-21-day-tapering-plan

That's the great thing about training (and coaching).
There isn't one plan for every athlete. Sounds like you figured your plan out.

I was just chiming in to say that people who win big races, from 2 minutes to 24 hours, tend to follow the guidelines that Coogan posted...
"1. The shorter the race/the higher the intensity, the more important it is to be fresh (i.e., TSB equal or greater than +10). Conversely, the longer the race the more careful you need to be to avoid resting too much/too long (and also the smaller the benefit of tapering in the first place);"

Maybe I need to find out what a TSB is lol...

I find if I’m too rested or too much tsb I don’t have the intensity in my legs for short course. Horses for courses

Interesting but it leave me with some thinking. If i go deep in overload (stravistix, works a bit like training peak) i definitely feel bad every time. An IM is such a high training score it'll let me deep in "overload" if i don't start from well rested. So it sounded fair to start the race as low as possible in "fatigue" in order to avoid crushing the overload ceiling too hard/too early in the race. But surely i'm overthinking.
What i lknow for sure is that no training in the week leading to the race don't work well. But i would have thought that i could train but only at low training load, to get that fatigue low while continuing to train. Bad guess ?

well my anecdote is that this is true for me. big acute training load means I can't go much faster than tempo, but can go tempo pace for a loooong time.