Depends on the product, cost of product and size of deals. Are you going to be an Account Executive or part of a sales team (are you going to be a sales engineer or a sales rep?)? Are you selling a one off, tactical, product or selling from a portfolio of products. How big is the company? What's the success ratio of people who have similar experience to you moving into this role at this company? Who will you be reporting to? What's their experience? How long have they been a manager? What's the voluntary leave rate for employees under the manager? What's the promotion rate for the employees under this manager? What's the success ratio for the employees who have been promoted by that manager? How do they set quotas? What are the revenue goals for the company? Are they reasonable?
In my experience, there are three things that make a sales rep successful. If you have all three, provided the product and demand is good. You have a 100% chance at success, one and you have 33%, two = 66%.
Existing relationships in territory. How many people, who can sign a PO, can you call on their mobile and they will call you back by the end of the day? This is good for sales and referrals.
Time in seat. How long have you been selling this type of product? What's your biggest deal? How successful have you been in the past?
Product knowledge. Do you know what you are talking about? Are you credible? Will people trust what you say? Will they trust you when you tell them the solution will work as promised?
Of course, people sometimes get lucky or unlucky. Your leadership will determine how successful you will be. There are lots of bad sales managers out there. There are some good ones. Keep in mind that the interview process is just as much you vetting them as it is them vetting you.