Verbals are with the coach, not the school, and the level of commitment varies by coach. Make sure you understand the parameters of the offer and do your due diligence on the coach.
The following was posted on UCS recently (Pulling Verbals)...
SEC coaches do not believe any Verbal made prior to the start of a player's Junior year to be binding on either the player or college. Either maybe release from the Verbal by notifying the other party. SEC coaches have been letting all the travel ball teams they deal with on this policy for over a year.
Also, many colleges will pull a verbal if the player gets into trouble, academics falter or the player fails to progress as a player prior to signing a NLI. Most college coaches when they verbal a player make it known what they expect out of the player to keep the agreement.