Nip And Tuck Meaning

(idiomatic) so evenly matched that the advantage shifts from one to the other, and the outcome is uncertain

Example: 1867, C.H. Webb, My Mexican Mines, at Harper's Magazine, page 461
  It was nip and tuck with me between holding on to my stock and being sold out; but by great industry and prudence I managed to keep a little ahead and my mouth above water.
1906, Jack London, Before Adam, chapter 12
  We broke away toward the north, the tribe howling on our track. Across the open spaces we gained, and in the brush they caught up with us, and more than once it was nip and tuck.
1951, Howdy Doody's Christmas
  Well, it was nip and tuck, but everything worked out fine. Santa Claus got there in time to bring toys to all the boys and girls.