A seven-wicket victory at Eden Gardens yesterday put England 2-1 up with just one match to play, and on course for a first series success here in almost 28 years.
The prowess of spinners Monty Panesar and Graeme Swann, and reverse-swing seamers James Anderson and Steven Finn, are a continued demonstration of the skills England's bowlers have perfected to prosper in India.
However, it was Cook's three successive centuries, culminating in an English record 23rd, and significant first-innings runs throughout the batting order in this third Test are a world away from the hapless performances against Pakistan which kicked the year off.
England's latest victory, achieved despite a last-minute wobble when the tourists lost their first three wickets for eight in pursuit of just 41, caused Cook to reflect on the difficult journey the side have taken in the past 12 months.
"We've had a tough 2012," he said. "But the way we've managed to quickly rectify a few of our problems is a credit to our coaching staff and the leadership of [head coach] Andy Flower. All of us as a batting unit had to have a look at our technique against spin and work out a method which suits each of us individually.
"We worked our socks off trying to improve our technique. Although we didn't get immediate results, we are now starting to."
Cook's first assignment as permanent Test captain, after Andrew Strauss retired last summer, will now result in a drawn series at worst and he has every reason to hope for better after the final Test in Nagpur. It all clicked for England in a 10-wicket win in Mumbai and then in Kolkata – apart from one dodgy session on Friday and yesterday's minor stumble – England barely put a foot wrong.
Cook has underpinned the last two victories himself. He described his dismissal for 190 on Friday as a "brain fade" but has little reason for such self-reproach now.
"To score 23 hundreds was a very good moment for me," he said. "I hope I can do it one more time."