number of backlinks very different from various sources

I am on a mission to find the best way to monitor backlinks and their influence on my sites..

so far i have (for the exact same URL) :
seopro giving me "84434" backlinks to the site
smartpagerank giving me "20784"
backlinkwatch "17413"
yahoo "25490"
google "162"

who the heck do i trust, this is crazy?!

 

Did you try using Google Webmaster tools

that will give you the full list of what Google see's as your backlinks

 

162 Links seems quite low especially when Yahoo is showing 25k+

 

You can also set this up in iGoogle. It's quite useful.

Webmaster Tools opens up a good understanding of your site, especially when combined with Analytics.

 

I agree wholeheartedly with this. Analytics is a great free tool.

When looking at competitor sites I use Yahoo, It's not amazing and does show a lot of the same sites and loose links randomly

 

google webmasters tool can only bring the correct backlink details.
use it

 

Sussing out your competitors is key. Yahoo is reliable enough if you're willing to scan through the backlink results. It also gives you an idea of what terms to compete with and whether you have the materials available to do so.

 

great, thanks for this, much appreciated

 

Agreed with other posters, get into google webmaster tools, very accurate and has some other nice features which you can use also. And yes it is free.

 

I use also google analytics and It gives me great result..