Chennai Super Kings

It is fair to say Chennai won the IPL with their auction strategy. They retained MS Dhoni, Albie Morkel, Suresh Raina and M Vijay ahead of the bidding, and then repurchased R Ashwin, Doug Bollinger, S Badrinath, Michael Hussey and Shadab Jakati. While the other teams spent time feeling their way into the season, familiarity in the ranks allowed Chennai to hit the ground running. The core was intact, and the new additions - Tim Southee, Dwayne Bravo, Suraj Randiv and Wriddhiman Saha - played their parts whenever called upon.

They were unbeaten, and looked unbeatable at Chepauk, but that was only one aspect of Chennai's home advantage. No other franchise could command the depth of home-grown talent that Badrinath, Ashwin and Vijay provided Chennai with. Unsurprisingly, the franchise's identity continues to revolve around the strong local flavour, while other franchises are yet to nail this particular aspect of their brand-building.

Dhoni remained influential as captain, and devastating with bat, hitting more sixes in the tournament than anyone who wasn't Chris Gayle. Once the play-offs began, Chennai were outright ruthless, trumping their closest rivals twice, with the assurance of a side that is used to winning. Consistency is a tough act to perfect in the unpredictable climes of Twenty20, but Chennai will begin their defence of the Champions League in September as favourites once again. And when IPL 2012 rolls around, don't bet against them, not least because the final will once again be played at their fortress.

Best moment: Ashwin's classic dismissal of Gayle in the final, setting him up with two offbreaks, before nailing him with a slider.

Worst moment: The hammering at Paul Valthaty's hands, which coincided with Chennai's only shoddy fielding performance of the season.

Key player: Badrinath provided the crucial conduit between Chennai's play-makers in the top order and their game-breakers in the middle. He produced five sublime half-centuries, excelling in both crisis and fill-your-boots situations, and scored at a strike-rate of 126.51 without playing a single unattractive shot.

Flop: None

Must-do for 2012: Chennai have perfected their methods over two seasons, and should be in good stead as long as they can repeat them next year.

Royal Challengers Bangalore

Terming Bangalore a one-man army would be a disservice to their well-rounded bowling attack, and to Virat Kohli's tremendous impact at No. 3. A year from now, though, most will remember IPL 2011 as Chris Gayle's tournament. Bangalore will be working overtime to find a loophole that allows them to retain him in their fold; if they don't someone else will snap him up at the first available opportunity.

In many ways, this was a breakthrough season for Bangalore, having let their biggest names go in spite of strong performances in the last two editions. Their faith in youth wasn't misplaced, though a couple of their big-ticket buys did disappoint. S Aravind and Syed Mohammad showed that Twenty20 excellence can come from unexpected quarters, but Saurabh Tiwary was a pale shadow of his swaggering 2010 version. AB de Villiers and Tillakaratne Dilshan struggled to match the lofty standards they set during the World Cup, but as long as Gayle was on song nothing seemed to matter. Bangalore had no trouble replacing Dilshan at the top once he left for England, but the rustiness in their lower middle-order probably caught up with them in the final. That, and the remorseless scheduling that left them having to play their last three games in four days, in two cities.

Best moment: The moment Chris Gayle signed on the dotted line.

Worst moment: The poor start to the final, when a needless overthrow allowed Chennai to shift gears and chug away to a quick start.

Key player: Bangalore lost only four of the 12 games Gayle played in. He did well in all the games they won, and was Man of the Match in six. He slammed more runs than anyone else in the tournament, and hit more than twice the number of sixes anyone else did, despite missing the first four matches.

Flop: Saurabh Tiwary was a big letdown, considering Bangalore paid USD 1.6 million for his services. He looked out of place at No. 6, and out of depth when he had to get going quickly in the end overs. A classic case of second-season blues.

Must-do for 2012: Bangalore will want to reassess their batting line-up which looked top-heavy right through the season. Tiwary, Cheteshwar Pujara and Mohammad Kaif aren't ideal options for the end overs, and they might consider pushing Kohli or de Villiers to No. 5.

Mumbai Indians

Mumbai had the best bowling attack in the tournament, and yet spluttered to a disappointing third-place finish. Inevitably, the batting was the problem, and Mumbai somehow never came close to addressing the issue. Sachin Tendulkar and Ambati Rayudu began the season well, but in the latter stages, struggled to score their runs fast enough. Tendulkar opened the batting with a different partner almost every game, and once Davy Jacobs was injured, the opening combination became a lottery of sorts.

Kieron Pollard was a huge disappointment with bat and ball, though he produced more than his share of wow moments on the field. Rohit Sharma's IPL avatar once again confused and confounded fans who are used to seeing him fritter away opportunities at the highest level. James Franklin produced two inspired performances to haul Mumbai past a nervous Kolkata, but that late resurgence ended too soon.

Lasith Malinga had a splendid season, while Munaf Patel's unflappability earned him a rich haul. Harbhajan Singh too excelled, relying on flight and out-thinking batsmen, notably with the new ball. Yet, Mumbai chose to ignore those options, and entrusted the unheralded Abu Nechim with the opening over in the final play-off. Against Gayle. In a knock-out situation. It typified the sort of muddled thinking that held Mumbai back this year. The over went for 27, Mumbai sleep-walked through the remaining 39, and that was the end of that.

Best moment: Rayudu slamming L Balaji's last ball into the stands in their last league game. It was the culmination of a chase that showed just how well Mumbai could bat, but unfortunately for them, it did not happen often enough.

Worst moment: The moment when Tendulkar handed Nechim the ball for the opening over of the final play-off. Things rapidly went downhill from there.

Key player: It is unlikely that any single bowler will ever have the sort of Twenty20 impact that Malinga made on IPL 2011. He was fast, he was ferocious, he delivered yorkers and bouncers with equal felicity and fooled several batsmen with his changes of pace. He finished with 28 wickets for the season, comfortably ahead of the rest of the pack, despite losing a bit of steam towards the end.

Flop: Kieron Pollard scored too few runs, and conceded them with far too much ease when he had the ball. His performances did not justify Mumbai's decision to retain him, despite the fact that he was arguably the best fielder in the tournament.

Must-do for 2012: The top order has to bat with more freedom. Tendulkar holds the key at the top, while Rayudu and Rohit may have to shore up the middle order. Mumbai may also consider giving Andrew Symonds a bigger role with the ball.

Kolkata Knight Riders

For a side that had never finished better than sixth before this season, Kolkata would be pleased and relieved to have finally broken into the top half of the table. In reality, they deserved to finish higher, if not go all the way, and they will forever be rankled by L Balaji's nightmarish 20th over in their final league game.

Still, there were plenty of positives for Kolkata to take from IPL 2011, and they were largely founded upon their decision to cast aside emotion in favour of pragmatism. For too long the Kolkata franchise had been associated too closely with Sourav Ganguly, rising with his smiles and floundering when he frowned. Their biggest accomplishment was the manner in which they introduced their initially diffident supporters (Eden Gardens was close to half empty for Kolkata's first home game) to the post-Ganguly era. They picked wisely at the auction, if somewhat lavishly, and in Gautam Gambhir, they found a worthy successor to Ganguly - demonstrative on the field, and graceful through the off-side. Yusuf Pathan and Jacques Kallis pulled their weight as well, but the real successes were Iqbal Abdulla and Manoj Tiwary.

In hindsight, Kolkata might regret the decision to push their batting arsenal lower down the order, but this is not the time to point fingers. For the first time in their IPL history, Kolkata have a team that looks good enough to go all the way, and that in itself is reason to celebrate, given all that had gone before.

Best moment: Balaji's stunning legcutter that befuddled Shane Watson early in the tournament. It was a ball that announced the new-look Kolkata and gave them the confidence to surge through the league phase

Worst moment: Ironically, Balaji's horror 20th over against Mumbai. He had 21 runs to defend, but served up four hittable full-tosses all of which went to the boundary. Kolkata never woke up from that nightmare, and subsided meekly in the play-offs.

Key player: Yusuf Pathan did not have the kind of batting impact he has had in prior IPL seasons, but that was down to Kolkata's decision to use him very low down. Still, Yusuf made 283 runs at a brisk pace, but he played a far more pivotal role with the ball. His flat offbreaks with the new ball earned him 13 wickets at a miserly 6.10.

Flop: There were no real failures, but Eoin Morgan was probably Kolkata's biggest disappointment. Kolkata were unsure of how best to use him, and perhaps erred in asking him to open. He scored 137 runs at 15.22, and his inability to get going at the top often put pressure on Gambhir and Yusuf.

Must-do for 2012: Gambhir was almost reluctant to open the innings through the season, since Kolkata did not want him and Kallis batting together. Given the depth in their line-up, with players like Ryan ten Doeschate and Shakib-Al-Hasan often wasted in the middle-order, Gambhir should consider opening with Kallis.

Nitin Sundar is a sub-editor at ESPNcricinfo