Minecraft – How to you test if a player’s scoreboard score has gone up with /execute

So basically, you have a command that makes 2 scores identical and a score you want to subtract:

/scoreboard players operations (player1) (objectiveA) = (player2) (objectiveB)

(note player one and player two don't have to be different)

Next you would want a command that you subtract from (objectiveB):

/scoreboard player operations (player2) (ObjectiveB) -= (player2) (objectiveC)

Then you have a player selector in the next command. For instance:

/effect @p[score_Output_min=1] minecraft:slowness (time) (amplifier)

and that will show it is working right if you do the same general outline of what I did. Hope this helps. Just heads up this gets complicated real quick and it took me forever to figure out what i did wrong. I hope this helps you understand and recreate the idea if you need it.

You can do this with just two command blocks:

1. Make a scoreboard objective with type "dummy" (referred to as [objective]
2. Make a repeating command block leading into a chain command block (both always active)
3. Set repeating command block's command to scoreboard players set @a [objective] 0
4. Set chain command block's command to execute @e[type=fireworks_rocket] ~ ~ ~ scoreboard players set @p[r=1] [objective] 1

This works because when you use a firework while gliding, the fireworks entity still exists and is constantly teleported to the player that used it. The first command reset's all players scores, and the second one sets any players who are rocket gliding score to 1, allowing you to execute commands on anyone who is rocket gliding.

Note: If a player lands while their firework is still active, they are technically still rocket gliding until the rocket runs out. Also, the fireworks will also set players score when placed immediately next to a player.