TerryI don't know the exact algorithm but it does work very well within limits (<20 cents and better <10 cents) and seems to auto set the overpull based on a trailing average.
I tried programming the verituner to do that (I have that program as well) but couldn't get it to work as well. This feature on CT I find to be an incredible time saver.
I agree with some earlier comments that the display is not quite as friendly as the SAT but it alsomight be a bit more sensitive. That can be modified in settings, btw. In the high treble it can be a bit bouncy. But you get used to it.
FWIW all tunings I do are two pass tunings. The second pass on pianos that don't have much pitch correction are mostly unison checks. In the case of a smart tune pitch correction of less than 10c I find that note corrections are rare if you are careful with the first pass. Greater than that it depends. 20c corrections often require some small note changes in some sections, but not all. Greater than 20c usually requires some section corrections, but, again, not all sections.
What it does do is get the first pass very close even on larger corrections so on the second pass the corrections are very small.
Of course, if the piano is out of tune randomly, some notes sharp some nota flat, it's less effective.
Paul M. wrote: "I use 25% in the bass and tenor sections, and 33% in the high tenor and treble past the tenor/treble break."I think the percent overpull you are using is close to what is generally recommended. I've wondered for a long time why it is that it seems to work better for me if I use larger percentages. On medium and large size piano I use 20% in the bass, 32% in the tenor and 42% in the treble. I've never understood that.
I think those numbers are too much correction.
If I were programming the Verituner for overpull I would start withBass - 12%Tenor - 25%First capo section start at 25% and graduate to 35% by the middle of that section and remain there through that sectionSecond capo section start at 35% through half the section and then graduate down to 15% by the time you reach C88.
Modify as needed.This will work pretty well with VT. With SAT or any device that doesn't actually measure each note as you are tuning and that are more limited in overpull selections it won't work so well.
I don't have any experience with Tunelab to comment there.