If you want to win then you have to be disciplined and not go chasing a bet, wait for a bet to come to you. I'll tell you a few recent stories of my own if you have time to read through them.
My particular favourites are when outside forces influence a price, forces which have nothing to do with the actual game but can affect it's outcome. It's pretty easy to spot these if you are really into a particular sport and they are particularly common in the likes of Ante-Post betting.
Some examples of outside forces for my own particular niche, Scottish Football include:
Rangers going into administration - it's been pretty well known for months that they were going into administration yet I could back Celtic at 9/5 when they were 1 point behind Rangers in the league in November (that price was left out by mistake by Unibet after Rangers lost and Celtic won that weekend). I had a few hundred on that price and I had my bank account on Celtic to win the league at 1/7 when administration was announced on Sky Sports News last week (they were 4 points ahead at that stage and administration was looking likely). I hedged out of the bet at 1/50 the next day on Betfair.
Last year I backed Gary Hooper to be top goal scorer in the Scottish League. I had around 400 each way at 25/1 when he was 10 goals behind Kenny Miller in the league. He was injured for the first 2 months of the season so had fallen pretty far behind. When backing the 25/1 I thought the win was unlikely but was more interested in the 7/1 place. The 7/1 place was so interesting because basically Kenny Miller was 8 goals ahead of the second top striker in the league at that point, so Celtic's top striker only needed to catch up on 3 goals to get into second place. I made the place about 1/2 myself. The only reason it was 25/1 was because the WIN ONLY was very unlikely, the place on this market was broken.
Not only this, but there was an angle for the win - Rangers were going broke and Kenny Miller was out of contract in the summer - so there was a huge chance they would sell him in the winter transfer break. Of course they did this and Hooper went from 16/1 to 5/4 to be top Scottish goal scorer over night (I backed the 16 win only too when Sky Sports News announced it). Unfortunately for me Hooper finished 1 goal off the lead in the SPL, but I made a few grand from the place as intended and got one hell of a ride for my money when Hooper scored a goal to bring him one behind top, 25 mins into the last game in the season (I had about 6k profit if he scored again and 12k profit if he scored 2 more ).
Of course there are examples of bets that haven't worked out so well. I backed Birmingham to go down at 33/1 this season because I believed there was a huge chance of administration, I backed Hearts to go down at 40/1 because of the same reason in the SPL (betting was suspended for a while on that one when the wages weren't paid). Overall though I have nicked several thousand in the last few years, just trying to spot the things that happen outside sport that will affect the prices.
I of course have short term bets some of which work and some of which don't - even the ones which you know are getting massive value.
An example of this is I backed Ajax to qualify from Group D of the Champions League this year. My reason for backing it was there was two games to go in the group and Ajax were three points and 7 goals ahead of Lyon to get into second place in the group. Lyon were playing Ajax in France in the next match, if Ajax won the match they qualified, if Ajax drew the match by any result other than 0-0 they were through (as the other leg was 0-0 and it goes on head to head), if Ajax drew 0-0 then Lyon would have to win in the final match and hope Ajax lost, whilst also reducing the 7 goal difference to less than 0.
Ajax were 6/5 to qualify with Bet365 at this point - but you could back Lyon at 6/5 to win their next game against Ajax with Asian bookmakers. This does not make sense, someone hasn't done the permutations - if Lyon don't win they are more or less out of the Champions League so if they are 6/5 to win the game then Ajax are 5/6 to qualify from the group on the night. Not only that but even if Lyon did win then Ajax would still be about 6/1 to qualify if they could better Lyon's result in the final game.
Overall I made the 6/5 being offered by Bet365 as an actual true price of about 4/6. I absolutely piled on it until Bet365 cut the thing to even money and even that was wrong.
So in the next game Lyon played Ajax, I knew and Ajax knew that a draw more or less got them qualified - I backed the 0-0 in the game (I was think it was 9/1) because I knew Ajax would be playing for it. The game ended 0-0, I won a few quid and my 6/5 bet on Ajax qualifying was now 1/25 top price with most bookies.
For any of you who know what happened next... Ajax lost 3-0 to Real Madrid in the final game and Lyon won 6-1. I lost several thousand pounds on a bet which was outstanding value and which touched 1.01 to lay In Running (and I didn't hedge).
But that's the way the cookie crumbles with gambling - you can do all the right things and lose and you can do all the wrong things and win.
The most important thing to know is if you keep doing the right things you will win in time, the only thing needed is discipline and managing your staking levels.