Pulses
Your sniper has a fixed maximum range. If it detects a locked sniper inside its range, it will start its firing animation.
However, the sniper isn't constantly checking what's in its range. If you're locked on to a sniper, it'll only check in pulses of X frames. So, once every X frames, it'll do a range check. If the enemy sniper isn't within range during the check, the sniper won't try to shoot. It'll wait for the next "pulse" or range check. This forms the "range check cycle".
What this means is, if you keep NLing, your sniper will sometimes shoot earlier (when they are further away) than other times. That's because the range check is sometimes happening just inside maximum range, while other times it's happening after your sniper has already moved a decent distance inside maximum range.
Now, the crucial element to all of this, which lets things like dlock/stance/slock work, and which is the foundation of what actually makes one sniper shoot before another, is this:
The range check cycle is specific for your sniper, and isn't affected by other sniper's action. The cycle starts when you lock, and it goes on from there. Even more importantly, the cycle RESETS if you lock again.
Why dlocks/stances/slocks work
DLocks work because the first click (on the ground) makes your sniper face the other sniper. The second click (the lock) initiates a range check cycle. When timed correctly, the enemy sniper is JUST inside max range when the first range check happens. Your sniper is already facing the other sniper, thanks to your first click, so it shoots very quickly.
Note: you read in the dlock section that it is also possible to dlock by locking on the first click as well as the second. Now that you've read the pulse theory, you can see why this also works. The first lock is just there to face the opponent sniper. The second lock then RESETS the range check cycle so it works in the same way as the mc+lock version.
As you saw in Relieve's dlock video, you can also "dlock" while running at the person. Again, this is no different to the classic mc+lock method. The important points are:
- You first make your sniper face the enemy.
- Then, you lock so your sniper attempts to shoot just as the other sniper enters max range.
Facing the enemy
Facing the enemy sniper before you lock is crucial. If you lock while you're facing away, you've either:
- Locked while they're out of range, in which case you're probably screwed anyway, or
- Locked while they're in range, in which case your sniper first needs to turn around before it can shoot. That means you've given your opponent a window to shoot you in. Since their max range is the same as yours, if they locked it efficiently they have time to shoot you while you're still turning around.
This is why walkstances are inefficient. If your opponent gets a good lock on you you'll probably die, instead of DKing as you would have done if you'd been facing them.
Pulling
Pulling before you dlock generally gives you a better chance of getting the kill. If someone comes at you trying to shoot you and you're stationary, they can easily lock you at the right time to maximise their range. If you pull first, now if they want to maximise their range they need to predict when you're going to turn back to shoot, and lock you at the perfect time. Since that's quite hard to do, most of the time they'll keep a lock as an NL. Then they're basically hoping their range check coincides with when you decide to lock so that their range is at its maximum. The person pulling has all the control over the situation.
Spamming
One thing you can try if you're following a pulling sniper, is to spam lock them. Since each lock resets the range check cycle, if you keep spamming then your range check is happening very frequently and you're likely to catch them at or near maximum range. However, this is generally risky as it's very easy to skip with this method, which is a much worse outcome than just praying an NL works. Personally I've found myself skipping while spamming way more often now than in the old SC, so I don't do it that much anymore.
A note on latency
In the previous sections, I've said that the lock must happen as your enemy sniper enters max range. To be more precise, your sniper must register the lock just as your enemy sniper enters max range.
What's the difference?
Input delay.
StarCraft has a built-in delay on your inputs, so if you lock a sniper on your screen, it'll take Y frames for your command to register on the actual sniper. For the range check cycle, what matters is when the sniper registers the lock. This means that:
- You'll have to lock BEFORE the enemy sniper gets into max range, because the sniper won't immediately register your command.
- How MUCH before you have to lock depends on the turn rate and latency settings in game. In the old SC (1.16) this was a long time before, because there was a ~500ms input delay on low latency. In the new SC the delay is much lower, so you can lock just before they enter max range and it'll register in time. If you increase the latency setting, you'll have to lock later. A good experiment to perform is to play around with the latency setting in a practice map and see if you can still perform dlocks. (Just don't do it for too long, it'll mess you up in a real game.)