If the New Zealand cricket team were a person, it would in all likelihood be BJ Watling. The numbers will tell you they are probably the best at what they do without there being much popular acknowledgement for that. But the numbers will have certain holes in them, however those holes will be there because they don't get as many chances as some of the others.
Let's look at Watling then. You might gawk at first if told he has been the best Test wicketkeeper of his time and the best that New Zealand have ever had. His record, though, bears it. Provided he is fit through the farewell leg of his career, Watling will retire with 76 Test caps, at least eight centuries - seven of which were scored in Tests he kept in - and close to 4000 Test runs to go with a largely unblemished career behind the wicket. Only Adam Gilchrist, Andy Flower, and Les Ames have scored more hundreds than Watling while keeping wicket in the same match.
Since Watling's debut, nobody in the world has scored more runs at No. 6 or lower. Only four New Zealanders have scored more runs in this period despite his batting so low in the order. Only Brendon McCullum comes close to his exploits as a wicketkeeper for New Zealand, but his batting suffered in matches that he kept wicket, scoring eight runs per innings fewer than when he played as a batter alone.
Watling has scored his runs with his own method, soaking up a lot of balls, nurdling ones around the corner, staying away from expansive drives, and cutting and pulling when tired and frustrated bowlers err. And he has tired and frustrated the best of them, that too at times when they don't have reasons to be tired or frustrated. Since the start of 2018, nobody has faced more balls per dismissal than Watling's 112.9 and 131.6 when coming in to bat at four down for under 100 and 150 respectively. The joke that goes around in New Zealand is that if Watling has failed the situation was probably not dire enough.
You are talking best wicketkeepers but discussing only runs scored and balls faced, you might want to say. Batting, though, is the currency in Test cricket today. The term wicketkeeper-batter is redundant because the batting is a given. Great specialist wicketkeeping is of course welcome, but it cannot come at the expense of a seventh or a sixth batter.
Nor is there any sophisticated measure to compare pure wicketkeepers in cricket today. Dismissals or catches per innings is a function of the quality of bowling and conditions. Catching/stumping efficiency is better but it still carries a lot of subjectivity. Shiva Jayaraman has worked out a statistic that might tell you Watling has been among the best pure wicketkeepers. Since the start of 2018, Watling has allowed byes only 47 times in 21 Tests, his rate of 2.2 per match being the best. Niroshan Dickwella is second with 2.4. Tim Paine and Rishabh Pant, by comparison, have allowed byes on 3.3 and 4.2 occasions per match.
Yet even amplified stump mics won't bring Watling in the popular conversation around the best wicketkeeper in the world. It is possible to pick out counterarguments. And there exist valid ones. A lot of his rescue acts have come at home where pitches just keep getting better and better as matches progress. He hasn't scored runs in India and Australia, two of the toughest places to play Test cricket in.
That is the kind of question mark you can place against New Zealand's record too even as they prepare for the inaugural World Test Championship final. They have been phenomenal at home, competitive in many countries, but haven't come close to threatening to win a Test in either India or Australia, the gold standard in Test cricket.
Then again how many chances do they get? India lost 4-0 in Australia in 2011-12, spent the 2014-15 tour playing a whole Test series and an ODI tri-series without winning a single match, but have kept getting their share of full tours of Australia. The same holds true for Australia and England. In the time that Watling has played Test cricket, seven teams have played more Test cricket than his New Zealand.
Ajinkya Rahane made his debut four years after Watling but has played the same number of Tests as him. Virat Kohli started out two years after Watling and is closing in on a 100. In Watling's career span, he has toured India twice. The first time was in 2010 when he played only one Test, making 6 and 2 not out, which effectively means he's had one proper tour of India. Perhaps Watling is not good. Perhaps he is and would have improved on his second and third trips. We will never know.
To Watling, it probably won't matter. Numbers and data are not all that you accumulate playing cricket. He knows he was good enough to last so long in Test cricket. He retires knowing he has been part of some of the most special wins and moments in New Zealand's history in Test cricket. He has had his hands battered by a red-hot, almost possessed Neil Wagner letting rip bouncer after bouncer. He has seen Trent Boult and Tim Southee set batters up from close. He has been the rock around which McCullum built his triple century, the only one in New Zealand cricket. He retires having experienced the toil of five days of high-quality cricket followed by a few beers with his team-mates. That feeling of just sitting back and looking at a group that has shared a space that only a few get to walk on: a Test field. Having won more than a few of them. Some from ridiculous situations.
We can continue debating if he was the best of his time. If he should be in an all-time New Zealand XI. He is not that bothered about legacy. He just knows he can no longer dedicate as much of his energies to cricket as are required to be at the level that he played. There's more to life. Perhaps it won't be as thrilling and exhilarating as walking in at four down with not many on the board with the best bowlers in the world chomping at the bit, but he has had his share of that.