I have ~50% of the skills needed for an open job. How can I prove my value for the rest?

I am looking to apply for a new job, and it seems like I have part of the background needed.

Part of the job asks for skill A, which my whole background is rooted in.

But, the primary function seems to be skill B.

I have some experience with skill B, but not enough where I am confident in my qualifications for the role.

While this new job (for a new team) seems to require more of skill B at the moment, I wouldn't be surprised if they start looking to hire more personnel with skill A down the line, as a supplement.

Essentially, they would want someone who has both skill A and skill B (more of skill B). But would they be open to someone who has high proficiency with skill A as well

How can I prove that my strength in skill A, and some experience with skill B is valuable to them?

And if I can't prove my value at this time, would it be possible to prove that skill A will be an integral function to have for their team later on (planting a seed for future openings)?

It's hard to know since we're talking broadly here, but my question is how difficult is it for you to learn skill b? Also, do you have any experience with skill b? Maybe you can talk in generalities for skill b if you get the interview.

I have some background in skill b, and was in a mentorship program at my current job for that skill. It was mostly high level, but I learned a lot. I def can speak in generalities, but wondering how i can leverage my mastery in skill A as the main selling point/most value for the team

So, I would actually avoid spending too much time talking about skill A. Maybe balance it like 30/70 (A to B).

Here's my thinking:

If someone wants a Marketer and someone is currently in Finance but wants to switch to marketing it wouldn't really work well for them to spend 100% or even 90% of the interview talking about their strength is Finance because--though marketers will need to manage budgets--we're not 100% certain if the interview is looking for that.

Instead, spend as much time talking about the thing you know they are looking for. In my above example, the Finance person should spend more time talking about any marketing projects he/she has been involved in and then maybe position his finance experience as more about analytics and ability to see what the market wants, analyze data sets, manage lean operations, etc. You want to position his skills in finance to make them relevant for the skill you know the job is hiring for. In this case, marketing.

So for you, spend as much time you can talking about skill B and if you need more examples then talk about how your experience at A is relevant to skill B. And, at the end of the interview, when they ask you if you have any questions, ask them if they will need people with experience in skill A and see what they say. If they say "Yes, that would be valuable" then jump into your deep knowledge there. If they say, "Nope. We just want skill B people." then go deep on how your experience makes you qualified.

Thank you! Solid advice that is applicable— cater my responses to this specific role, and relate my experience to what they’re looking for

And it’s a great idea to connect/pepper in my expertise to how it fits the role