When you're hunting around the different bookmakers and online casino operators for free bets and bonus cash etc., you'll quickly notice that it's the casinos that seem to offer the biggest bonuses. This is particularly true for new players. The casino bonuses are generally much larger than normal bookmakers' free bets and introductory bonuses – but they almost always come with a few strings attached.

The terms and conditions usually state that you have to play a certain number of games before you're allowed to withdraw or transfer any of the free cash from the site. And as the house edge is always working against you in games of chance in casinos – the tendency for most people is to erode their bonus money.

But at the same time, the online casino business is tremendously competitive so the bonuses are very large to begin with. And you can sometimes win as you play through, of course. So it's very often worth picking up the biggest free cash offers you can find, then playing as carefully as you can at games like roulette, for example, where you have a fighting chance of coming out even. Then – and here's the key thing – you can transfer the bonus cash from the online casino to the sports book account and pick out a few bets where there is far more judgement involved; as opposed to games of pure chance.

So it's important to choose the best bonus sites that also run sports books. In this way, you can maximise the free money and, hopefully, have a fair bit left to transfer to sports betting.
At the Betfair casino, for example, you can pick up a 200% matched bonus if you're a newly registering casino player. If you decide to play slots on Betfair, you can do even better – getting up to £400 as a welcome bonus through the 400% slots bonus.

Of course, Betfair is far better known for its sports betting and other "judgement call" markets than it is for its casino and slots games etc. If you're a new customer to Betfair's mainstream (non-casino) site, you currently qualify for £50 in free cash. This is no bad deal in itself, but you can get a lot more via the casino – if you can then hang onto it.

As for which markets to choose thereafter, the world is your oyster of course. The traditionally popular markets such as the Barclays Premier League and UK horse racing are seemingly bottomless on the exchanges these days.

Other sports, meanwhile, including cricket, both codes of rugby, Formula One racing, snooker and darts are all huge markets. But if there's one sport where you can really get an edge by following the game closely, it's surely tennis.

For tennis experts, it's possible to find betting "Nirvana" sometimes if you have in-depth understanding and expertise. Obviously, any given match is a two horse race. But you have to know the sport, the players and the tournaments inside out.

With the tennis Grand Slam events, like the forthcoming US Open, for example, all the top players will be going all out in every game, with every conceivable detail covered. But in some of the lesser tournaments, the form doesn't always hold quite as true as players may be experimenting a little with different techniques etc., and you simply can't replicate the high pressure of a really big tournament. In other words – games can be anomalous so the basic premise is one of finding odds of 2.05 or better with Betfair (the .05 to cover the site's commission) on matches where you believe a player backed has at least a 50-50 chance of winning. In this way - you'll come out ahead over time and if you can start with free cash, then why not?