Spin bowling is a wonderful art in cricket, where one needs to know how to control the amount of revolutions given to the ball. In International Cricket we can see many players trying spin bowling in part-time basis. From this many ppl are thinking that spin bowling is much easier than pace bowling . For any bowler the main thing is line and length, but for spinners in addition to these things the ability to bowl long and tidy spells is also an essential one.
For a spinner the encouraging thing is beating the batsmen in flight.The best thing they can do in pitches outside subcontinent is contain the batsmen and pile up the pressure in one-side and let the pacemen attack from the other side and grab wickets. In these pitches slip and short leg are a must for a spinner. Now and then the spinners too take wickets with the bounce available in the wicket and the turn which they can get on the fourth and final day. The final and penultimate day pitches in any test match favours the spinners.
In sub-continental wickets spinners play a major role in deciding a team's fate than pacers . Most of the sub-continental pitches are made for spinners since all sub-continental teams have spinners leading bowling attack. Here the pitch starts turning right from day one and as the match progresses the pitches ll bcome a ranked turner. In these pitches the spinners need to flight the ball as much and need to get the purchase out of the wicket . Also the captain needs to attack with closing men around the bat, so that the pressure can b applied.
In ODI's the job of a spinner changes depending on the situation of the game. Now a days the spinners are bowling lot flatter in the limited version of the game which makes them to b played easily. For a spinner to survive in international cricket now a days he needs to b having variety in his bowling. For an offie doosra is a weapon which can get him wicket and make him unpredictable and now a days some offies are bowling theesra which i have no idea :P. For a leggie they are developing the art of googly and flippers which provides them with the variety.
Controlling a leggies in not a easy one. So i would rate the "Spin Wizard" Shane Warne ahead of the "Legendary" Muttiah Muralitharan.