Aircraft told two mins delay due previous same route so offered backtrack to which they accepted. I was flying with a very senior and respected training Captain (large European airline ) to which he said
“why backtrack do they have no understanding of aircraft performance. .... idiots “
anyway it was a short flight and never got to ask him why.
I began thinking of TODA TORA ASDA BALANCED FIELDS CLEARWAYS etc all being calculated from a certain point and would these be invalidated if you started your take off run say 309m earlier , airfield and terrain dependent of course ??