Somerset best placed to make the cut
With only three matches to go, Group B is still wide open, with all teams having a theoretical chance of making the semi-finals. Here's what each team needs to do (and what they need other teams to do) to qualify for the last four.
They're currently sitting on top of the group with four points, but whether they make the next stage or not depends largely on what they do in their final game, against Somerset on Wednesday.
If they win, they're through. If they lose, it could get complicated: they'll have to hope that South Australia lose to Royal Challengers in the last match; else Somerset and South Australia will both have more points and will qualify. Even if South Australia lose to Royal Challengers, Warriors will have to ensure they don't lose to Somerset by a margin that will pull their net run rate below that of Kolkata Knight Riders, who have four points and a NRR of +0.306. Warriors are currently on +0.592, but they don't have much room to manoeuvre: if they're chasing 140 against Somerset and lose by eight or more runs, their NRR will slip below that of Knight Riders.
The weather in Bangalore has had most teams fretting, but the one side which will welcome rain is Warriors. One point in the last game will leave them with five, which means Somerset will be the only side that could go past them. South Australia could reach five points as well, but their NRR is languishing at -0.775: they'll have to beat Royal Challengers by at least 67 runs (if they bat first and score 160) to go past Warriors' NRR.
Kolkata Knight Riders
Kolkata have played all their matches and their fate rests entirely on the hands of the other teams (and the weather). If all three matches produce decisive results, Knight Riders' best chance is this: Somerset lose both their matches, while Royal Challengers win theirs. In such a scenario, Warriors will move to the top of the table, with Knight Riders and Royal Challengers tied in second place on four points. If Royal Challengers don't win by huge margins, Knight Riders will stay ahead on NRR.
Knight Riders will also go through if Somerset beat Warriors by a margin that is enough to pull the Warriors' NRR below that of Knight Riders (see the write-up for Warriors above). In this case, South Australia will have to lose to Royal Challengers so that they stay on three points.
Somerset are the only unbeaten team in the tournament so far, and with three points from two games, they have an excellent chance of making it to the next stage. One win in their next two games will almost certainly get them through. Even if they beat Royal Challengers and lose to Warriors, and if South Australia win their last game, Somerset and South Australia will be level on points, with Somerset currently far ahead on NRR.
With three points in three games and a terrible NRR, South Australia's equation is fairly simple: they must win to give themselves any chance of making the semi-finals. Even if they win, they'll have to hope other results go their way. If Warriors beat Somerset, who in turn beat Royal Challengers, then South Australia will most likely miss the cut even if they win their last game.
Royal Challengers Bangalore
They're the only team not to have won a match in the tournament so far, but if they win their last two matches, Royal Challengers may yet have a chance of qualification. To do so, they'll have to go past the NRR of Warriors or Knight Riders (depending on the result of the Somerset v Warriors game). Royal Challengers' NRR is currently -0.648, but if, for instance, they score 140 in their last two matches and win them by 25 runs, they'll sneak ahead of Knight Riders' NRR.
However, if either of their two games is washed out, then Royal Challengers' Champions League campaign will end before the semi-finals.
S Rajesh is stats editor of ESPNcricinfo. Follow him on Twitter