I have the rules for the current version of McDonald’s Monopoly, and am aware of how “collect-and-win” prizes work (there is one “rare” piece in each group - they tend to be the same from year to year, presumably so nobody will try to use previous years’ “common” pieces). However, I don’t understand how they get vastly different odds for groups that have the same number of potential winners.
It used to be that the listed odds of winning were based on how likely it was to get the rare piece - for example, this year, there are 674,373,700 pieces, two of which are Boardwalk, so they would say that the odds of winning the million dollar prize were 1 in 337,186,850. However, there are 20 Ventnor Avenue pieces (yellow) and 20 Kentucky Avenue pieces (red), but the odds of winning the yellow group prize are about 1 in 500,000,000, while the odds of winning the red group prize are about 1 in 162,000,000. (The odds of getting the Ventnor Avenue piece are about 1 in 33,720,000.)
It says the odds are “based upon obtaining the complete Winning Combination,” but it does not say how those numbers are determined.
Then again, I would not put it past McDonald’s to make some common pieces more common than others, for two reasons; to entice people to keep playing (if there are more Park Places than Baltic Avenues, for example), and to make it harder for anyone trying to collect all 17 common pieces to complete their collection.
Oh, and does “I have Park Place; if you have Boardwalk, we’ll split the money” (or “I need any of the following, and will split the money - Boardwalk; Pennsylvania Avenue; Ventnor Avenue; Kentucky Avenue; Short Line Railroad; Tennessee Avenue; Virginia Avenue; Vermont Avenue; Mediterranean Avenue”) tend to show up here anywhere (e.g. on Marketplace)? Actually, since every game piece is actually two pieces, a few years ago, McDonald’s started putting Park Place pieces right next to the Boardwalk pieces, probably to prevent this sort of thing.