Bishan Singh Bedi, while chatting to spinners, always mentioned the fact that spinners should use the wind to good effect. He spoke extensively about the benefits of bowling into the wind so that you could make the ball drop on the batsman and how the sideways wind should be utilised to extract drift in the air. While it all made a lot of sense, I seldom found the spinners he was teaching putting his advice in practice. Perhaps, either the stadia in India didn't allow the wind to enter (or at least it isn't strong enough to really have an impact) or the spinners in question weren't good enough.
Later in my career, I had the privilege of playing with and against some quality spinners and most of them displayed the ability to both drift and dip the ball in the air but it wasn't so much about the wind. While the dip was about their skills to put enough revolutions on the ball, drift was because of using the body and shine of the ball to good use. As the game has progressed and keeping in mind the demands of white-ball cricket, especially in T20s, the presence of drift and dip has reduced significantly. While the modern-day spinners have added the mystery to the mix, they seemed to have compromised with the age-old art of making the ball move laterally in the air forcing the batsman to play down the wrong line and making the ball fall a foot shorter than the batsman expected it to land. You need to bowl below a certain speed to allow these two factors to play a role but most white-ball specialists have started bowling faster.
Indian spinners in the first three New Zealand ODIs
These pitches in New Zealand are reasonably flat and the grounds are really small. The moment a spinner finds these two factors going against him, he tends to up his pace by a few kilometres. Both Yuzvendra Chahal and Kuldeep Yadav have spun a web around the New Zealand batsmen but without bowling faster. In fact, they've not only bowled slower but also used the wind to their advantage. Both of them had their opportunities to bowl with and into the wind and they figured out different tactics to be effective. While bowling with the wind, Kuldeep bowled a lot of legspin and while bowling into the wind, he bowled a lot of wrong'uns.
When you bowl into the wind, the ball drops on the batsman but the flip side is that he hits you with the wind and therefore, even mis-hits end up going over the ropes. While Kuldeep has used his variations, Chahal has used subtle variations in line beautifully. His biggest strength is that he consistently bowls outside the line of batsman's arc and that's exactly how he has operated in New Zealand too. In the third ODI in Mount Maunganui, the wind was blowing from his left to right and while bowling to Ross Taylor and Kane Williamson, he kept drifting the ball into them and made sure the ball pitched outside hitting zone. Williamson's dismissal was also an example of how Chahal pushed the ball into the body and also made it dip a fraction. Similarly, the way Taylor got out in the first ODI in Napier was a result of ball dropping a little shorter than he expected and therefore, ended up looping it back to the bowler.
New Zealand batsmen's flawed approach
If the pitch is flat, you play spin with the straight bat. Try and play down the ground as much as possible by either using the feet to go down the pitch or by going deep inside the crease. That's exactly how Indian batsmen have played the New Zealand spinners. Virat Kohli is a prime example of how it's done, for he neither steps out nor does he sweep and yet he's brilliant against spin because he plays them down the ground as much as possible. Well, you can argue that Kohli is exceptional.
But let's have a look at most New Zealand batsmen's approach against the Indian spinners, including Kedar Jadhav. They've tried to play them square of the pitch with a horizontal bat very often, which isn't a bad option if it's a dust bowl but it is a flawed tactic on good surfaces. Till you don't drive the spinner down the ground, he's unlikely to bowl short enough for you to manoeuvre off the back foot. And that's exactly how the Indian spinners have operated.
There are two key benefits of bowling a fuller length - it forces the batsman to play an attacking shot (which in turn increases the wicket-taking chances) and it doesn't give the batsman time to read the spin off the surface. The latter has been an issue for some of the New Zealand batsmen, for not all of them are able to read the spin from the hand. Their only recourse, when that happens, is to try reading off the surface but usually the ball is so full that they're unable to do so.
By bowling slow, using subtle variations and the wind to good effect, the Indian spinners have done what most spinners have struggled with in New Zealand conditions - they have successfully clipped the Kiwis' wings. Pun intended.