I am shooting basketball 1/200 f/2.8 ISO 1600 on my 1D, and the images are really noisy and have some noticeable motion blur. When I shoot with flash, the motion blur goes away but I still have the noise issue. Can I crank up the power of my flash and turn down the ISO? I see it as "cheating," using the flash to like... replace the ambient light.... I think.

Would this work, or am I better off investing in some arena-type strobes? I'm not sure how much longer I will be shooting basketball, but I just need to figure out the ISO noise issue. Any help is appreciated.

If you can get 1 more stop from your flash on your subject, then try ISO at 800 and reduce shutter speed to 1/100 to maintain the same ambient exposure and see if the flash is dominant enough to freeze the action with it's shorter duration.

Good luck

If you are indoors ALL the light is artificial so does it really matter which artificial source it comes from? Intensity-wise not really. Direction-wise, yes if you want to avoid a flat on-camera flash look.

The solution has two parts: 1) enough power to cancel out the ambient light, and 2) positioning the flash so it mimics the normal downward omni-directional ambient court lighting. Mind you that ambient lighting direct typically isn't very flattering, creating dark shadow in eye sockets due to shading by the brow.

You've touched on the ideal approach. Huge Speedotronic flash units placed in the four corners of the court triggered by radio. Check over at sportshooter.com and you'll find lots of information on how the pros do it.

If you want to do something similar on the cheap any additional flash power you can get up above the action would be helpful. It doesn't necessarily need to be in front either. Behind is actually better for action shots. The combination of fill flash on a bracket on the front of a subject combined with back-rim lighting provides separation and defines shape with the backlighting while the frontal lighting with the downward angle provided by the bracket reveals the frontal detail in a clear natural looking way without distracting dark shadows:

Either try Carmen's suggestion (solving noise from high ISO) or try flash with same ISO 1600 and 1/100 shutter, or get a lens faster than f/2.8 (more ambient exposure, solving noise from underexposure). It's likely to be one of those.

Carmen Miranda wrote:
If you can get 1 more stop from your flash on your subject, then try ISO at 800 and reduce shutter speed to 1/100 to maintain the same ambient exposure and see if the flash is dominant enough to freeze the action with it's shorter duration.

Good luck
I will have 2 flashes on one end of the court. They will be attached to the ceiling somehow (the basketball court has a really high ceiling, I'm not sure how I will hang the flashes) and triggered with ebay slaves. Recycling time isn't a big concern, I'm just trying this out to see if it's worth getting Alien Bees or something better. So If I hang them in the corners, pointed to spread light around the center, by the goal, and set them to say, 1/4th power, would that be good enough? I'm wanting to go < ISO 1250, between 1/200th and 1/500th, f/2.8 maybe 1.8. I'm really not sure how this is all going to work out, so thanks for all help!

For power and exposure you'll just need to test. Look into Bogen-Manfrotto super clamps for attaching your flashes to things. The one below is equipped with an extension arm: