This isn't a pop quiz. Running in is a) Lasith Malinga, b) Jasprit Bumrah, or c) Mitchell Starc. Whose yorker do you not want to be facing? No stress. There is no right answer to this, just some background reading if you chose 'a' or 'b'.
Since the last World Cup, nobody has attempted to bowl more yorkers than Starc. On average, every eighth ball he has bowled since then has been a yorker, or an attempted one - the latter, by ESPNcricinfo's data collection, includes full tosses, the logic being that a full toss is usually a yorker gone wrong. Only Malinga bowls one more often, and only marginally so. Only Bumrah has taken more wickets with the delivery - just one more. In any case, that's exactly the kind of company any yorker needs to be keeping.
Unlike those two though - and, in fact, to a greater degree than any of the other top five yorker bowlers since the last World Cup (in terms of wickets taken) - Starc and his yorker seem trapped in some kind of co-dependent relationship. It used to be so with Malinga, but he's transcended that and become so much more than just a yorker bowler with a weird action. Bumrah could be, except he's already so much more than a yorker bowler with a weird action. Trent Boult might not even strike you at first as someone with a deadly yorker and Kagiso Rabada is so potentially GOAT that the yorker is a mere needle in his vast bow. Albeit one which, as Andre Russell recently discovered, still pricks just as hard.
Starc's fortunes somehow can be both chained to his yorker and liberated by it. If he's bowling well, the yorker is the obvious door to his greatness. Quite simply, it's the delivery that makes him - nothing else comes close. The bouncer is mean, but the quintessential Starc experience is to see stumps being hit from a full, swinging yorker and Slats in the background shouting "Trademark Starc!"
But when he's not, it's the only ball he seems to have and so could conceivably be called a one-trick pony; although as champions of Waqar in the eternal two Ws debate would have it, what a one trick.
The yorkers themselves have much going for them even without the aid of an unusual action. He is high-armed and fairly orthodox, unlike Malinga, and he doesn't have that lash on delivery that makes Bumrah so difficult to pick. He gets enough dip and/or tail and late enough so that because batsmen lose balance in adjusting, the beautiful illusion of Starc's yorker is that it gets faster the longer it flies. Like bouncers are said to get big on you, a Starc yorker looks like it gets quicker on you the closer it gets.
And the curves they sometimes cut are pure 90s throwback, each of them carrying the whisper of the greatest LAF ever (don't even dare throwing an 'M' in there - peak Akram was as quick as anyone). As an aside, like Akram - with whom he is now level for five-fers except in 279 fewer ODIs! - once Starc gets one wicket, he's twice as dangerous: since his debut, only Malinga and Boult have taken at least two wickets in six balls more times (21 times for Starc, 24 and 25 for Boult and Malinga respectively).
That pace is important. Yorkers work best at high pace: three of the top four wicket-takers with yorkers since the last World Cup are three of the fastest bowlers in international cricket and a fourth, Boult, is not slow.
Pace can be transformational. Against the West Indies, not a single one of Starc's five wickets were classified by ESPNcricinfo's analysts as actual yorkers. There was a full toss (let's allow that as an attempted yorker), a couple of half-volleys, and a full-length ball. All of them, in theory, could have been attempted yorkers but it didn't matter that they weren't - Starc's speeds, generally touching 150kph, can upgrade even half-volleys to yorker status.
How much he relies on it is borne out by the numbers. He is consistently first or second in the percentage of attempted yorkers he bowls across all phases of an ODI innings.
What stands out is his work with the yorker in those middle overs. Since the last World Cup, nobody has more attempted yorkers in this phase (to a batting line's top seven); Malinga has bowled a slightly higher percentage of yorkers but Starc has been the most successful, with five wickets. On average, he bowls three times as many attempted yorkers across the middle of an innings as Bumrah.
When it's such a weapon, why not? Could you quibble it's a crutch? Is it enough? A bowler like Starc should, instinct says, have more to his game. It should not seem, as it occasionally does, that he's bowling in the wrong decade, though equally, he has a World Cup win and an outstanding ODI record to emphatically prove that he isn't. And his death bowling against West Indies had much more flavour.
But equally, he's one of those bowlers who, when he gets the yorker right, it gets everyone asking why more yorkers aren't bowled today?
Well, much has happened to the yorker over the last decade or so, not all of it good, but not all of it bad either. It's probably bowled better than it used to be, just that its success or otherwise is measured differently. The space for the right yorker, as Nasser Hussain once demonstrated so simply and smartly, has shrunk through a combination of regulations and batting advances. In all this, it's also worth remembering that the yorker has never been an easy ball to bowl. In terms of skill, of course, but Akram always thought that physically, yorkers took more out of him than bouncers did.
That's the flipside of this co-dependency though, isn't it, that the yorker itself needs bowlers like Starc to liberate it from its modern-day captivity.