I also started with the anime. It only takes half of the story that is shown in the manga. If you decide to watch, you can continue the manga from chapter 82 (which shows the end of the game last seen in the anime) onwards.
I've watched several shows based on high-stakes games or sports as the theme. None of them have impressed me to the same degree as this series. If this manga was offered in Canada, I would probably buy it.
I have always loved watching baseball more than almost any other sport. The ridiculous gambling bets and the battles of wits are a bit of a thrill ride at times. Others they can be very predictable and you find you're observing more for the tactician aspect. Predictability isn't necessarily bad, it's how it's written and I think the author writes in such a way that even something you can predict is still enjoyable to read (at least in my opinion).
Overall, if you're a baseball fan and enjoy a good battle of wits read, I highly recommend this.