First let’s look at some of the advantages of both one- and two-handed high catches.
One-hand grabs have the obvious advantage that you can reach an inch or two higher, partly because you can twist one shoulder higher than the other, and partly because not fully raising that other arm will slightly reduce the effect of gravity on your centre of mass. Lots of people will tend to go one-handed for maximum height.
But two-handed grabs are not without their advantages – one obvious, one fairly obvious, and another much more long-term.
The obvious advantage is security – two hands make the disc less likely to escape you.
A nearly-as-obvious advantage, but one which is often overlooked, is the creation of a barrier. If you go up one-handed, your defender can swing a hand through the disc almost any way they like without contacting your arm. It’s relatively easy for them. But two-handed means you have an arm both sides of the disc, and you probably also have your shoulders and hips squarely blocking the defender too – you won’t be catching high discs two-handed from side-on very often.
Look again at that top picture, and think about what sort of bid that defender has (although on this occasion he doesn’t look close). Now imagine that the offence had gone up with two hands, and think about where the defender could possibly put their arm that would get the disc without fouling.
Your arms blocking the defender’s arms, and your square-on body position preventing them getting around you, are both very significant advantages for a receiver. It’s far, far more likely that they’ll have to foul you to get to the disc if you go up with both hands.
Because of that first advantage (making the catch more secure), you’re perfectly entitled to go up two-handed as a natural way to choose to catch a disc, and if that just happens to impede the defender then that’s neither illegal nor unspirited. It’s just sensible. It’s not at all the same thing as jumping with an arm out to block the defender, which would of course be illegal.
And there’s also another advantage – people who prefer to catch two-handed generally do a much better job of being in the right place. This is because the brain learns from its mistakes, and therefore needs a way to define a mistake.
If you go up one-handed and misread it slightly, then you catch it a bit left or right or forward of where you thought, and no harm done (unless the D gets there, of course). Many people in fact end up learning to catch out to the side of the body, as in the bottom picture below – which gives the defender a route to the disc. You’re very unlikely to register a slight misread and will mentally put it down as ‘good enough’ – right up until that guy skies you in the big game six months from now.
But if you go up two-handed and the disc is a foot or two away from where you expected, chances are you’ll have to grab at it with one arm.
This is already a better situation, because you’re in a much better position to react to a misread since both arms are already up there in the vicinity. [In this picture, there’s been a misread with the right hand, but the left would have been in just the right spot to make the grab. Also note again how the defender has a free swing.]
But it also allows you to register the misread as a mistake. You still caught the disc, but the two-handed catch attempt was a failure. You succeeded as a receiver, while at the same time making an error and learning from it. That’s a fantastic thing to be able to do – make mistakes, learn, and yet still back up your team-mates while doing it. People who use two hands a lot become better, faster, at reading the disc.
So: what does all this tell us about how to attack high discs? Ignoring for now the long-term learning benefits, it tells us that there will always be a trade off between catching at the highest point and keeping the opponent away from the disc.
In situations where you’re competing for a disc with one or more other players, the major determining factor will be your position. The player with position – generally the offence – should usually use two hands, and the defender just one.
On defence, you don’t really care too much about making the catch more secure, so two-hands loses that first advantage. And if you’re out of position – usually, that’ll be the defence – there’s not much point creating a barrier. Instead, you probably want to be more side-on so that you can squeeze past the offensive player more easily. Going two-handed and squaring up the shoulders might actually make life harder for you.
And of course the extra couple of inches from going one-handed still applies. So for the defence it’s a no-brainer to go one-handed.
[A note on this picture. You can see that the defender has gone with one hand, out to the side of his body, in order to get around the offence player. But note that the offence is trying to catch it outside the line of his body also – whereas a two-handed attempt would have necessitated having the disc directly in front of him, putting his body between the defender and the disc.]
And for the offence? I’d say that whenever you have even slightly better position than your opponent, two hands is the better option. Almost all the people I think of as ‘owning the sky’ – certainly all the ones who aren’t 6’6″ or have a 35-inch vertical – prefer to take it with two hands. Unless you can take it genuinely that much higher than your defender, then it’s probably far more important to impede his attempt than to reach your own maximum height.
You might lose two inches by going up two-handed, but chances are your defender will lose a lot more than that.