What are follow-on rules? Why won't Australia enforce follow on vs India?

The 3rd Test between Australia and India has reached an interesting stage at the moment with day 4 seeing India clinging on and trying their best to build up a good partnership a top order meltdown in the 1st innings.  While rain has interrupted the proceedings multiple times, India need to post at least 246 runs in order to avoid a follow-on being enforced on them by the hands of the Aussies today.  What is a follow-on in cricket? 

The follow-on is a tactic used in long-format cricket, such as international Tests and domestic First-Class matches, where each team typically bats twice. It can only be enforced once three innings have been completed, and it allows a team to force the opposition to bat again immediately after their first innings.

 

The decision to enforce the follow-on is made by the captain of the team that batted first. If the team holds a commanding lead, the captain may choose to enforce the follow-on in the belief that the match can be decided quicker by bowling the opposition out twice. According to Law 14.2 of the Laws of Cricket, the captain must notify the opposing captain and the umpires of this decision, and once made, it cannot be changed.  What is the minimum lead required to enforce a follow-on?

 

The minimum lead required to enforce the follow-on varies depending on the match's length. For five-day Tests, a team needs a 200-run lead. In domestic First-Class cricket like the Ranji Trophy, the requirement is 150 runs. In shorter matches, a lead of 100 runs is needed for two-day games, and 75 for one-day matches. Law 14.1.3 adjusts the lead if the first day is washed out.

  Teams opt for the follow-on to increase the chances of a result by tiring out the opposition quickly, capitalizing on their low total and fragile morale. It also boosts the bowlers’ confidence, though it does come at the cost of player fatigue.   Why Australia won't enforce a follow-on on India?  With India not too far from reaching the total needed to avoid a follow-on, it is expected that the Aussies won't be getting the chance to do so because of the start-stop sessions in Brisbane giving the Indians some relief as they aim to keep the scoreboard ticking at the moment. 

With just one day remaining in the Brisbane Test, enforcing a follow-on may not be the right decision if the Aussies aim to produce a result in a match largely disrupted by inclement weather conditions.

 

On the other hand, Australia might choose to bat for one session and set a target for India to chase instead.

  India would hope to avoid the follow-on as the last time they were the recipients of a follow-on in Test cricket, was back in 2011 when the England enforced it at the Oval and eventually won the series by a 4-0 margin.  However, the last time Australia enforced a follow on on India in red ball cricket was back in 2001, which saw India eventually coming out as the victors at Eden Gardens. With that being said, it will be a difficult task to get the victory Down Under after a dismal showing with the bat by the Indians in the 3rd Test so far. 

Victory after a follow on in Test cricket history
Winner	Margin	Opposition	Ground	Match Date
England	10 runs	v Australia	Sydney	14 Dec 1894
England	18 runs	v Australia	Leeds	16 Jul 1981
India	171 runs	v Australia	Eden Gardens	11 Mar 2001
New Zealand	1 run	v England	Wellington	24 Feb 2023