If you land the aircraft in the way the Boeing, training manual specifies you will attain the required landing performance every time. No need to have a separate short field or long runway technique. Do it the same every time and the performance requirements will be met. Now, there is room for error and the wiggle room the performance calculations give you is less on wet runways and almost nothing on contaminated. You’ve also got to make 100% certain the auto speed brake deploys, the auto brakes activate, and the reversers which may normally only be brought to idle are used straight away, at maximum reverse. If you land long and/or one of the autobrake, speedbrake or reversers are not activated, an overrun may well be on the cards. Read through the NTSB reports on the AA 757 overrun, at Vale, the SWA, Midway overrun and the Eastern, La Guardia 737 overrun to see how a short runway and a braking system failure or late selection can cause trouble fast.