A +1.5 spread is commonly seen in baseball betting, the standard runline  for MLB. This spread means the underdog must win outright or lose by exactly one run to cover the spread. Alternatively, a -1.5 spread means that the favorite must win by at least two runs. Many baseball games are decided by fewer than two runs.
Even bets shelter you from a draw\n\n Evens/odds bets don't take into account extra time or penalties, meaning a draw is always possible. Moreover, a draw is always even. In this sense, betting on an even number of total goals can be a plus to protect your stake a little more.