The more Hertz the better when it comes to fast-moving action.
Just like LCD monitors, LCD televisions have a refresh rate, which is measured in Hertz. The refresh rate basically refers to how often the image on the screen changes. This shouldn't be confused with response time, which is how long it takes a pixel to change colour. Nor should refresh rate be confused with frame rate, which refers to how many frames per second are including a video clip.
You'll get the best picture if your refresh rate is a multiple of the frame rate, eliminating the need to invent extra frames.
How refresh rates improve your picture
Television refresh rates initially corresponded with the frequency of mains power, which is 50Hz in Australia and 60Hz in the US. Doubling the refresh rate significantly smooths out the action, reducing stuttering and jagged lines during faster moving scenes. For example, straight lines on a football ground are more likely to look straight when watching a 100Hz television, as are the pickets in a fence as you pan past it quickly.
Upping the ante
This 100Hz technology has trickled down to plenty sub-$2000 LCD televisions and you can certainly see the difference if you pay attention. Vendors such as Sony and LG have upped the ante with their 200Hz LCDs, but these are more expensive and the improvement on 100Hz isn't as striking as the improvement from 50Hz to 100Hz. US models offer 120Hz and 240Hz models, but that's only because they're working on multiples of 60Hz rather than 50Hz.
Brand names
Every manufacturer has its own name for boosting the refresh rate, for example Sony calls it Motionflow while Samsung calls it Auto Motion Plus. Don't be confused with the "Sub-field drive" Hertz rate quoted by some manufacturers, such as 600Hz from LG and 550Hz from Panasonic.
This can be confusing, as isn't the same as the refresh rate for the entire panel.
Motionflow 200Hz certain helps smooth out motion on the new Sony Bravias, but it can make movies look a little too crisp - as if everything is computer generated. You'll want to tweak the Motionflow, Cinema Drive and Noise Reduction settings to your liking for different content.
If you're serious about your sport and are considering LCD rather than plasma, make sure the television offers a refresh rate of at least 100Hz.
Buying a flat screen TV? Have a question you'd like us to answer? Add your comments or questions about flat screen TV issues to the discussion below.
Also in this series, How to Pick a Great Flat Screen TV, And Not Get Sucked In By Marketing Hype:
Part 13: How do I compare HDTVs in the store?
Part 12: Hiding your television
Part 11: calibrating your television
Part 10: those pesky upscaling issues explained
Part 9: video inputs and future proofing
Part 8: Logitech Harmony vs AV Link remote controls
Part 7: Should you upgrade your TV for DLNA?
Part 6: TV tuners and "Digital Capable"
Part 5: HDMI and component ports
Part 4: LED and backlighting
Part 3: Screen size
Part 2: Refresh rates
Part 1: Brightness and contrast ratios
Also see our 5 tips for buying a digital TV set top box
And also see the lowdown on Freeview, and whether you should care
If you're new to Digital TV, or have yet to make the leap, start by reading Prepare yourself for Digital TV