On my Minecraft world, I've always made it possible using the Execute command to get a speed boost in ways. This was in the 1.12.2. Now I opened it in the 1.14. As far as I know it was already changed in 1:13. Now I can't see through the command and could not find a suitable answer yet.
The command I used so far was: / execute @e [type = Player] ~ ~ ~ detect ~ ~ ~ grass_path 0 effect @s speed 1 1
/ execute @e [type = Player] ~ ~ ~ detect ~ ~ ~ grass_path 0 effect @s speed 1 1
Will not work, as you said. Here is a derivation of what the new looks like:
The command / execute has changed completely. It has now become one of the most powerful commands, see https://minecraft-de.gamepedia.com/...hl/execute for more info.
What do you have to change now? You have to say from now on, if you want to select a player, with as. In addition, you have to select its position yet, with at. How does that look then? So:
/ execute as @a at @s
Then you want to test the block in the player, it should be a grass_path. You have to do that with the if block-statement. To stop the execute command, you must run.
/ execute as @a at @s if block ~ ~ ~ grass_path run
So, now we select all players who fulfill the criterion and can address them with @s. Now the speed effect, which was also changed something: https://minecraft-de.gamepedia.com/...ehl/effect
The final command looks like this:
/ execute as @a at @s if block ~ ~ ~ grass_path run effect give @s speed 1 0 true
Hope that helps!
Many Thanks! Finally it works again!
Always happy!
If you need more, then I can help you even further!