Toss-Up Meaning

(idiomatic) A decision in which neither choice is clearly favorable or unfavorable, or for which the outcome does not matter.

Example:   It's really a toss-up between the red skirt with blue stripes and the blue skirt with red stripes. They both look good and fit well.
Either of two outcomes that are equally likely.
2013, Tom Shone, Oscar nominations pull a surprise by showing some taste – but will it last? (in The Guardian, 11 January 2013)[1]
  No longer is the best picture going to be a toss-up between that troika of national-historical heavies: Argo, Lincoln and Zero Dark Thirty. Instead, a warm welcome back for Life of Pi, widely dismissed by many as "this year's Hugo" but this column's dark-horse pick from October.
The toss of a coin used to decide some issue.