It is a well-known fact that the best way to study for the SAT is to take many official practice tests. But, unfortunately, the testing environment that you will face at your actual SAT will be nothing like your practice tests. It will be more intimidating and full of more distractions that will break your concentration and negatively affect your strategy.
This shift from practice conditions to actual SAT conditions often contributes to a score drop in many SAT takers. If you want your practice test score to be completely predictive of your actual SAT score, you must simulate real SAT conditions.