Need expert advice on monitor issue

I have an old Mitsubishi CRT monitor model number XC-3730c.
I play first person shooters on my PC and have been using large CRT monitor of the like for many years. The back has BNC connectors with R,G,B, also with a gray and black input BNC connectors. So five total. Red green blue gray black. I assume the gray and black wires are for horizontal and vertical scanning of some sort.

What I dont understand is why when I play my games on this Old monitor from 1996 the game play is super smooth and fluid like. When people move it looks and feels like in real time and it is easy to aim at them.
Then I hook up the PC to a Sharp Aquos 60 inch LCD HDTV. It actually has a VGA input and is labeled "PC input" so there is no need to change the display option(such as Game mode or cinema mode and so on)
The game is slightly choppy. It isnt fluid like and smooth like the old CRT is. Its harder for me to follow players because of the choppiness. Even i tried a LG 55 inch LED HDTV and it is the same thing. not perfectly smooth like the Old CRT monitor is. Why is this?... and how can I find a new display that is large and will give me my perfect smooth fluid game play that i get from the giant CRT monitors that are so Big and heavy?

Changing the refresh rates didnt seem to do anything and I thought it would.
Any questions please ask....thanks

The CRT display will give a smooth playback because of the persistance of the phosphor. The standard phosphor used in computer CRT's will smooth out the picture (through persistance) holding the image on the screen until it is redrawn. there are also different phosphors that allow faster screen updates without creating motion blur.

For the LCD there is no real persistance (there is a limit to how fast a screen will update) and there is no smoothing between adjacent pixels like on a CRT that can make images look nice.

The only way to compensate for this on an LCD is to use very high refresh rates, which you cannot normally do on TV LCD's.

Those extra 2 BNC connectors are for horizontal and vertical sync (input) together with the other three R, G, B connectors.

To make it better you need a screen that supports a higher refresh rate (which yours may but check the specs for the different inputs) together with a graphics card with enough power to run smoothly at high refresh rates for the games you play.

Usually the HDMI input will give you a better picture with higher refresh rate support then the PC VGA connector - check the TV specs to be sure or let us know the model and graphics card you have and someone might be able to help.

Both the tvs say they go to 120hz but on tv won't change at all when I try change the refresh rate and the other tv lets me go to 75 hz but it doesn't help smooth out the game play. I don't hdtvs are really meant to give monitor quality for gaming. I don't know what to do. Do I have to search on Craig's list for old crt monitors that are huge to be happy with my game play? Why don't they make a tv or monitor that is large that will give smooth perfect game play like the old crts do?

Not only that.... The old crts that I was using only go to 60hz refresh rate. Plus I had to even lower the refresh rate on the graphics card for the monitor to display the picture. The computer I have now is top of the line in everyway.... Using windows 7... There's just something not right here.....?......

The monitor may go to 120Hz but probably not using the VGA input, check the detailed specs or let us know the exact model number of the TC and Graphics card and we might be able to comment more specifically.

I tried to explain the technology is very different. LCD has no persistance (image holding) like phosphor in a CRT.

For good game play on a LCD monitor (not LCD TV) you need a high resfresh rate (so image movement looks smooth to the eye) with a fast pixel response time (usually around 2-3ms) so they do not blur.