Most veterans here are talking more of Bookies than the connections n owners. Bookies are primarily Bookkeepers and they will always prepare books/or take bets which will balance out their books!.

Their primary goal is not to predict the outcome perfectly but to make a profit regardless of who wins. 

Their profit comes in the long run indian racing season start in May and end in April. So November, December, January and February is set for bookmakers. 

It's just a guess while opening odds, finally market demand will decide/stabilize odds, a 10/1 at opening may close at even,  a even money at opening may close at 10/1 depending on market demand

UK Bookies are grizzled veterans who know the horses inside out.

I once placed a bet with a racecourse Bookie and joked "I am feeling generous, so I decided you should take my money". He replied "I most certainly will". He was right!

On the other side of the fence, I was once in the Parade Ring at Goodwood, and I was introduced to someone who said: "I backed your horse at Kempton two days ago" (It had won). I later remarked to my companion - "How does he know our horse?". He informed me that this fellow was the biggest Horseracing gambler in the UK, and even knew the odds on our horse in a relatively minor (Class 2) race.

These people live and breath the Sport, and follow the form very closely.

Grey haired HANDICAPPERS are responsible for ODDS all over the world where descent races are conducted....

Real HANDICAPPERS are not like one of the most knowledgeable horse racing brain of the country like MR.PRAKASH GOSAVI (inventor of Dynamic Handicap) or those genius brains(who refer their selections based on handicap) of this portal..... Handicapping of thoroghbreed racing horse is a science with a syllabus and mostly taught in a couple of countries in Europe.... Australia and USA. Horse racing is basically a fight between Handicappers and Trainers.Rich centres recruits qualified HANDICAPPERS with dream compensation packages.

Usually Decent Speculative Owners.. Trainers...Jockeys and very big punters used to place BETS to illegal BOOKIES all over the country and these BOOKIES are well connected to each other and these BOOKIES hired the said HANDICAPPERS for the opening ODDS and as betting progresses they change their ODDS. These said illegal BOOKIES are connected to a couple of BOOKIES of the RING of each racing centre..... Now these RING BOOKIES after getting the ODDS of the outside BOOKIES play with the ODDS which is their solo WEAPON to confuse the most intelligent punters and all. And this pattern of playing with the ODDS is still not DECODED in this planet.

Friends.... Now it's up to you.... Whether you believe it or not.... But the FACT is that this is the process of making of ODDS.

There is also a myth that connections make heavy bets a night before or in the morning much before race. 

There are small bets that happen at night odds. That too such bets are not from the connections. Such bets are basically hard core punters who are ready to gamble on anything and don't have patience even for morning. 

Even in the morning there is betting but not heavy one. The actual heavy betting starts just around half an hour to an hour before race. There are doubles and triples placed in good volume. 

Also just to give you an idea you may have seen a horse at 3.5 in morning odds and opens in the ring at 5/1 or 6/1 and then gets fancied in place and runs on the board. 

This is because in the morning the connections ask the bookie that they want to eat the horse xyz amount at suppose 4/1. So now this bookie has his odds highest compared to market and he will take them to 5/1 as he knows connections are eating it. 

Gradually horse opens at 5/1 or 5.5. And has a even money place. Now the connections back it well in place. And the horse doesn't win but places. 

There are many reasons why odds rise and fluctuate. 

Raceing is pure gambling based on Mumbai mataka.

Their will be a group of well racing knowledge people from many bookie 

They will give  90% correct odds 

Otherwise bookmakers will be in docks 

Only on tote we can not decide

All over the world almost bookmakers will hv the team of knowledge racing people 

Odds will b depending on handicap weight  jockey and the merit of horse penetrara meters 

Finally whether the horse owner has a bet on his horses 

Trying or untrying it will be known only 5 minutes of race

Hope I hv cleared all ur doubts 

Regards

Good luck 

See it is like this..when you buy a race book,you will see usually 3 choice,how they arrive to that , that's the point..You and Me we buy the book to study and zero on to a perticular horse of choice.. Imagine bookmakers do business in huge amounts ,put how much effort..It's all in one's own way to act

I will explain the traditional method of deciding odds. 

7 handicappers give their choice of 1/2/3 in every race. 1st choice carries 3 points, 2nd choice carries 2 points and 3rd choice is 1 point. So a maximum number of points a horse can get is 21. Such favorites are money back. Say something like Be Safe, Southern empire or Seargent at Arms has at 2000 Guiness. 

Now it's not a mandatory rule that the horse has to be money back. Bookmakers as per their wish can raise the odds if they want to take the chances. 

So as per the points given to each horse the odds used to be decided.

These days there are worldwide bookmakers who decide the odds and all refer to them. But odds on board can be higher or lower depends on bookmakers personal fancy. 

And trust me odds give a strong indication but at times are also misleading. 

Very good topic. The "BOSS" who decides the odds is from Kolkata as per reliable sources. Private betting happens with him a day or two before and then there is a software which analyses the chances, then experts opinion, then the odds come out. This is just as per my knowledge/sources only

@come on,a very good and needed question! Had queried too years back. It's a fact that the odds are out by around 9-9.30 a night before. Who decides is something that would reveal a lot of things.