usually for most monitors. except early electrohome and wells gardner 4600 raster scan's , most yoke wires are 4 pin plugs now. The two wire closer to each other on one side are the vertical output. The other half of plug the wires are just a little more apart then the other side so you cannot mix up and put them on vertical side pins.
Always check and measure with meter. vertical will measure from few ohms to 8 ohms.
horizontal will measure from .06 to a couple ohms depending on monitors.
usually the horizontal wires are a thicker gauge then vertical wires also. usually.
just like carpentry, measure twice, blow up monitor once.
yes, even i sometimes have to move the yoke wires around because i did not really look the first time to see if horizontal is flipped,etc....