The KBG probably won't choke out the fescue, but it will fill in bare spots. However, KBG spreads via rhizomes rather than stolons. Rhizomes should be below ground. You may want to take some of the weedy grass (including some roots) to your extension service to your extension service to get an accurate ID. I've seen blades of grass from the same plant get identified as two different grasses from pictures. It can be very difficult to ID grass from pictures. Many grass seed mixes have fescue and KBG in them. I think some types of fescue may mix better with KBG, but K31 grows much faster and has much wider blades, so I think a mixture of KBG and K31 fescue tends to look somewhat patchy. Where in WA are you? You may be better off seeding in the fall. It may not matter as much if you're in the Seattle area, since it rains so often there, but if you're inland where it gets hot and dry in the summer, a fall seeding will give the grass more time to establish before the hot dry weather hits.

Thanks for the replies. @ Tiemco so Tall fescue is the type of seeds I need to buy for that bare spots? Sorry is that's a dumb question LOL! Here is the bare spot in the front. Below are a few pictures of the rear. @ Newrandwest I noticed the tearing when I was reviewing the pics. I have a push mower & that it a brand new blade on it. Do you have to sharpen new blades? I just thought about it. I used a pellet type of weed & feed shortly before the guy at the store told me to try the liquid kind. I only treated the front half of the yard with that & I treated the whole yard with the liquid. I dont know if that was too much for the grass but I believe the pellets are the reason the front looks pretty green & half decent. I didn't use the pellets in the back because money was getting low plus the back was in really bad condition & needed a lot of work. The yard has a little incline up to the canter then it goes back down & that kinda hide the rough parts from the front. Here is the main problem spot in the front yard. From the front porch Up close Dead? Under the side extension for the kitchen Back yard. You can see the weed killer are keeping those little white flower things in the other yard Is if my yard wasn't jacked up enough... Thanks Direct TV guy! If I could get my entire yard to look like this part in the front I would be very happy :-)

Contact your counties office of your University of Georgia Cooperative Extension Service about controlling " Poa aqnnua". This publication from them may be of some use also. http://extension.uga.edu/publications/detail.cfm?number=B1394 kimmq is kimmsr

I live in the same area as the OP, and that looks very much like yellow nutsedge, Cyperus esculentus. A real pest, and not easy to get rid of. I've had some success with pulling/digging, making sure to get the roots and nutlets if the latter have already formed. There are also herbicides formulated specifically for nutsedge.