You can't possibly put up every scenario - well, maybe you could, but i"m not Joey Brackets - but a bunch have Purdue has the No. 4 seed in the Big Ten Tournament, if things play out in a reasonable fashion over the last three games.
Purdue could still win the title. One interesting way would be to win either at Ohio State and Michigan State, plus Illinois, going 2-1. Maryland also could go 2-1 (you'd think that's the worst they could do, considering the schedule: Rutgers/UM at home; road at Nebraska), and Wisconsin 0-3 (which isn't unthinkable, but is unlikely). Then, three or four (depending on whether Purdue beats MSU or OSU) would be tied at a 13-5 record.
The way I see it, the only way Purdue drops to the 6 is if it goes 0-3 and Iowa goes 3-0, with wins at PSU, at Indiana and home to NU. Purdue can also still lose out and still be the 4, if Iowa goes 2-1 (L vs. Indiana), MSU goes 1-2 (Ls at Wisconsin and at Indiana), OSU goes 2-1 (L vs. Wisconsin) and IU goes 2-0. It would create a five-way tie for third. OR, if MSU goes 2-1 in the above, winning at Wisconsin, creating a four-way tie for fourth, with Iowa, Indiana and OSU. (Purdue has enough tie-breakers in those to be No. 4, and also causes my head to explode).
Purdue would be fifth if it goes 0-3, Iowa goes 2-1 and MSU goes 2-1, assuming the Spartans' loss is to Wisconsin.
Purdue can also be fifth if it wins vs. Illinois, MSU goes 2-1 and OSU is 3-0 (If Purdue gets to 12 by beating Illinois, the outcome of that Wisconsin-OSU game is going to matter for Purdue's tie-break scenarios to be 4 instead of 5). Pretty sure that's the only reasonable way Purdue can win vs. Illinois and still be fifth. Most others have Purdue being a 3 or 4, at least as far as I can tell, if it gets to 12 wins. For instance, if MSU goes 1-2 (with road loses to Wiscy and IU), Purdue only beats Illinois, then it goes up to 3 (with other reasonable expectations elsewhere).
Now, read that 17 times.
Purdue could still win the title. One interesting way would be to win either at Ohio State and Michigan State, plus Illinois, going 2-1. Maryland also could go 2-1 (you'd think that's the worst they could do, considering the schedule: Rutgers/UM at home; road at Nebraska), and Wisconsin 0-3 (which isn't unthinkable, but is unlikely). Then, three or four (depending on whether Purdue beats MSU or OSU) would be tied at a 13-5 record.
The way I see it, the only way Purdue drops to the 6 is if it goes 0-3 and Iowa goes 3-0, with wins at PSU, at Indiana and home to NU. Purdue can also still lose out and still be the 4, if Iowa goes 2-1 (L vs. Indiana), MSU goes 1-2 (Ls at Wisconsin and at Indiana), OSU goes 2-1 (L vs. Wisconsin) and IU goes 2-0. It would create a five-way tie for third. OR, if MSU goes 2-1 in the above, winning at Wisconsin, creating a four-way tie for fourth, with Iowa, Indiana and OSU. (Purdue has enough tie-breakers in those to be No. 4, and also causes my head to explode).
Purdue would be fifth if it goes 0-3, Iowa goes 2-1 and MSU goes 2-1, assuming the Spartans' loss is to Wisconsin.
Purdue can also be fifth if it wins vs. Illinois, MSU goes 2-1 and OSU is 3-0 (If Purdue gets to 12 by beating Illinois, the outcome of that Wisconsin-OSU game is going to matter for Purdue's tie-break scenarios to be 4 instead of 5). Pretty sure that's the only reasonable way Purdue can win vs. Illinois and still be fifth. Most others have Purdue being a 3 or 4, at least as far as I can tell, if it gets to 12 wins. For instance, if MSU goes 1-2 (with road loses to Wiscy and IU), Purdue only beats Illinois, then it goes up to 3 (with other reasonable expectations elsewhere).
Now, read that 17 times.