This is a question that many answer in the negative. what is an"good speaker"? It's actually someone who connects with the audience. There is a difference between a "good speaker" and someone who can influence opinion while speaking before an audience of any size. I think the better terminology would be"good influencer". TED talks can be found on youtube.com. As you observe the speakers, you may notice that the presenters, by and large, are not what people would call good speakers. However, they do persuade. Most of them actually read a prompter with a narrative that was written with feeling and passion for the subject. The subjects usually fit the presenter. They are very comfortable with their subject and have great conviction about the subject matter. That conviction is projected to the audience. I have presented to audiences of all sizes and on various topics. The response from the audience has varied. The subjects I am most passionate about have received the best audience acceptance. My performance must be respectful of the time that the audience has invested. They are taking a certain amount of time out of their lives to listen to what I have to say. I must deliver a message that has value. If it has no value, even the best presenters will not connect. Subjects that are presented by passionate speakers are always well received.
My speaking history began with a passionate disdain for speaking, however, I knew that my career was dependent on overcoming my fear of presenting. Accepting failing grades in school in order to avoid a 2 minute book report was normal. I failed an entire year of English because of my refusal to present. So, I am no stranger to this phenomenon, but the embarrassment of failing is worth the achievement of improvement.
When presenting your practice, remember to discuss those elements of what you do that you are passionate about. Tell stories that illustrate your passion. Your audience will connect.