The International Cricket Council will shortly debate whether tests should be shortened to four days. Those advocating truncation - and most test-playing nations appear to - have powerful facts on their side.After all, the first two England tests against Pakistan finished within four days, and a similar outcome has been all too frequent recently: 41.5% of matches have ended before the fifth day in the past five years.The game at Lord's was superb and had enough fluctuations of fortune to make it compelling for four days. The one-sided rout at Old Trafford could have ended in three had the weather not intervened and had England enforced the follow on.story_article_left 1That evidence makes a strong case for four-day test cricket - especially since a generation of cricketers bred on the short-form game plays test matches as if they were limited-overs games. Run rates are way above where they were 20-30 years ago and opportunities for enterprising bowlers have increased accordingly.Australia merited four-day tests in the 1930s, but with an over-rate of 20 or so an hour (usual until the 1960s) four six-hour days were enough for 480 overs: 30 more than are expected in a five-day test now.If we are to have four-day tests again - and they or three-day games were the norm until Donald Bradman's last tour in 1948 - then shorter scheduled matches will change test cricket. Should it become easier for a bad side to hold out for a draw than it is now, that consideration will affect the long-term balance of the international game.A game being cut from a possible 450 overs to 360 will be less of a test, because poor batting sides will find the draw more in reach. People say it is unrealistic to insist on, say, 105 overs a day, even though that means lifting the notional rate merely from 15 to 17 overs and three balls an hour: but even 105 overs would only be 420 overs in the game. A generation or two ago 450 overs in four six-hour days would have been considered routine: fewer than 19 an hour...