Odds of +200 mean you can winR$200 on aR$100 bet, but there's no quick way to determine the implied winning probability. If these odds appeared as fractional odds 2/1 you could quickly solve for the implied winning probability using this formula: Decimal / (Numerator + Denominator) x 100%
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.