Tour de France 2009
12 Achievements
200
6-8h
Polka Dot Jersey (Difficult)
Win the Polka Dot Jersey in Difficult mode
10
How to unlock the Polka Dot Jersey (Difficult) achievement in Tour de France 2009 - Definitive Guide
You could technically get it at the same time as going for yellow by following my method there, but if not then just attack on all the mountain stages. Either with around 50 kilometers to go to try to win the stage (only if it's a mountaintop finish), or if there are alot of mountains before the finish line and the finish is after a downhill section then you might wanna attack earlier to get as many points you can get. Remember to pick a climber for this though, Contador would probably be the easiest and you can also win the yellow jersey with him if you're trying hard enough.
Also if you manage to mess up or if you have bad luck you could always just exit and reload the save, this works if you're not too sure about what to do too so you can try out this method and figure out what seems to work the best for you.
The Polka Dot Jersey is awarded to the cycler who, at the end of the tour, has the most climbing points. Throughout mountaineous stages you get points for reaching the top of a hill as first, second or third. The higher the hill, the more points you get. You can also get points for the stages which ends up a hill. Now, instead of trying to get the first climb point like the Green Jersey, the best way to get this jersey is to let your main cycler (the one going for the Yellow Jersey) to attack right when you climb up the last or second to last hill and make sure he gets there first. Basically repeat the process explained under the "Yellow Jersey (Difficult)" achievement and you will probably get it.