India are coming off a strong Test season in 2017. They lost only one Test match in the year and have lost only two since January 2015. If you go by the numbers, India are the team to beat.

The last time India lost a Test series was in Australia during their tour in late 2014. Since then a purple patch coupled with an extended home season have made Virat Kohli’s team seem unbeatable. But there is a caveat to this record-breaking run. Barring a brief series in the West Indies, this young Indian team has barely played outside the subcontinent.

India’s biggest Test cricket opponents are England, South Africa, Australia and perhaps New Zealand. Their record against these countries playing in their backyard is dismal. India have failed to win a series in South Africa and Australia. They’ve only squeaked five Test series wins between New Zealand and England since they started playing Test cricket in 1934.

All in all, Indian cricketers simply can’t play in conditions unfamiliar to them, a fact that has been sidelined due to their current run of form.

In 11 visits to Australia and six to South Africa, India have never won a series. In 17 visits to England, they have three series wins. In nine visits to New Zealand, two series wins.

It’s not a stretch to say that India is terrible away from the subcontinent. So for all the brouhaha of India’s incredible Test form, history is stacked against them this year when they travel to South Africa, England and Australia.

South Africa in particular is a daunting test. They have arguably the best bowling attack in the world, which bowled out a Zimbabwe side twice in one day last week.

Though India enter South Africa with renewed vigour since their last tour, they have historically done badly. Since their first tour in 1992, they’ve won only two Test matches. The most recent victory was a 87-run win at Durban in December 2010. Cheteshwar Pujara is the only player in the current squad who played in that Test.

That batting line-up included Sachin Tendulkar, Rahul Dravid and VVS Laxman, arguably India’s greatest Test batsmen. All three averaged greater than 40 at home and outside the subcontinent.

Only seven Indian batsmen in history average above 40 both at home and outside the subcontinent and fortunately two of them are in the current Indian line-up. But barring Virat Kohli, Ajinkya Rahane and an inexperienced KL Rahul, almost no Indian batsmen in current squad has done well abroad.

India’s ability to score big at home has been the main driver of their success. When batting first at home, the team piles on an average 354 runs in the first innings. But scoring big abroad has never been the forte of Indian batting. Outside the subcontinent an average first innings batting total is 295.

Relying on a few batsmen may become a problem. Despite a few players with overseas experience, only three in the current squad have scored more than 1,000 runs and average above 40.

A typical strategy in South Africa would be to bat big and scuttle out the opposition with some devastating pace. So even if the Indian batsmen do click and somehow manage to replicate their home batting form in South Africa, it’ll be upto the bowlers to defend these scores.

To win, the Indian bowlers will need to claim all 20 wickets in the match. Outside the subcontinent, India have taken apart a batting line-up 47 times in 190 Test matches. India have won 24 and drawn six of these matches. So 63% of their matches have not resulted in defeat when they bowl effectively.

But Indian bowlers aren’t really a force to reckon with. Of the current mainline bowlers for the South Africa tour, all skew towards playing well at home, with the exception of Bhuvneshwar Kumar who averages around 30 both at home and away.

Though Ishant Sharma, Mohammed Shami and Umesh Yadav are clearly quality pacers, they are significantly better at home. Yadav averages 41 away and 30 at home. Shami has the best hit rate at home with 23.34, but is 38 away. Sharma is the most consistent, but his average is relatively high compared to the other pacers. He weighs in at 38 away and 35 at home.

Owing to unfavourable conditions, Indian spinners don’t do well at all outside the subcontinent. Ravindra Jadeja and R Ashwin have had an incredible home season, but that really can’t be expected to continue in South Africa.

The contest to watch out for in the South Africa-India series is how the visitors’ relatively newly minted batting line-up dukes it out against the likes of Dale Steyn, Kagiso Rabada, Vernon Philander and Andile Phehlukwayo – all of whom generate pace that consistently hover close to 150 kilometres per hour.

Though Kohli is aware of the challenge that lies before him and his team, this will probably become a Test series that defines his Test captaincy especially in light of the great run of form over the last 18 months.