When a pros play a hero in a league, they have optimized that hero to the core.  Item build, skill build and general animation the hero makes.  Everything is accounted for.  I will be touching on the effective skill point distribution in this entry.  It's quite an effort to level up in DotA, and you always want to have the maximum value for your point spent.  One of the first question you should have of the hero is this: Can this hero afford a stat build?  If so, is it worth it?

Note: To me, skill and spell are the same thing.  Skill point, spell point, level point.  All the same as well.  I hope that helps on killing some possible confusion.

"But I'm missing my cool new ability!!"

You might be missing an ability.  But is that ability worth a point?  You see, stats set a bar (standard) to spells.  If some are deemed worse in value in comparison to stats, then stats are taken as an alternative.  The thing is, stats are actually quite high in value.  So the spells and skills of the heroes must have even higher value to be taken over stats.

Here are some heroes that can afford to have a stat build: Juggernaut, Sven and Spectre.
And I'll go over these heroes explaining how they can fashion a stat build.  Once you understand the raionale, it becomes easy and you can apply your knowledge to all the heroes.  The same question, "can this hero afford a stat build?  If so, is it worth it?"

Sven is easy to figure out.  He has a target AOE stun spell which is high priority.

You obviously don't want cleave early in the game for two reasons: One, your damage is so low in early levels that cleave adds little to your strength.  And second, your cleave does contribute to pushing the lane which isn't something you would normally like early game.  So you often do not take the cleave until it is in later stage of the game until you can actually pump some threatening damage.

Warcry is an interesting spell.  The difference between level 4 warcry and level 1 warcry is rather minimal.  The big difference is really the cooldown and armor while the movement buff stays the same.  You can either take it, or not take it.  It's really up to you.  Often times, the first point of the skill/spell usually grants the most value per point spent.  This is because it is the difference between nothing to something.  The value of this skill plummets once the first point is spent.  And therefore you should question if the next three points are worth spending into over stats.

Jugg is interesting because while he is able to afford a stat build.  It's possible for him to take other paths.  But it is usually much more standard to have a stat build.  His spin is definitely high priority.  However, one of common mistakes of Jugg's point distribution is the early takings of his crit.  And I think that's because people just love to see him jump and slash down in 90 degree angle with red text flying.  It looks cool.  But in means of effectiveness at early levels, it's questionable.  Jugg doesn't do nearly enough damage in early game for it to be effective and majority of your early game DPS comes from blade fury anyway.  It is advised that you hold the crit until later.  The healing wards usually have better presence in latter stage of the game as well.

Stats give this hero the HP, MP, damage and everything good.  But it's also important to note that it gives that small boost of attack speed which this hero really needs for his ultimate to be most effective.  Every bit counts, it really does.

Spec used to be a pretty standard stat hero before her dispersion change.  I've chosen this hero as an example because she isn't really easy to figure out like the other two.  It involves a bit more thinking and reasoning.  One thing to be noted here is that I am not going out of my way trying to make stat build work.  But rather, it's the question of "is it worth it over stats?" 

Let's look at her dagger.  The first level of any spell is usually the most important.  So that's granted.  The second point gives her more damage, and 4% boost.  The third point gives her more damage and 5% boost.  But the 4th point gives her again, only 4% more boost with addition of damage.  Now, the damage is a steady 50 increase per level.  Whereas the movement speed difference is 5%-4%-5%-4%, see the pattern?  Now, you question if it's worth taking that last point because you've already taken the meatiest part of the meal.  Can we throw it away now? 

It really depends on the game and the heroes you are against.  But let's see why we take dagger in the first place.  All good things aside, it's really for one main reason; chasing power.  So then, the question becomes "is level 3 dagger sufficient for chasing?  Or is it not?"  You get the idea.  The decision is up to you.

Another skill to look at is desolate.  And this skill has a lot to debate for.  It's little hard to evaluate the exact usefulness of this skill because it's really situational.  As you can imagine,
it's not something you can easily measure.  There are usually two sides on this.  One side views this skill as more than excellent will gladly max it over stats.  Some are more skeptical, only taking one point because it gives most value per point (note that first point of desolate gives 15 whereas it only adds 10 more damage per level).

Stats are actually higher in value to Spectre than maybe most other heroes out there thanks to dispersion.  The more HP she has, the more she can reflect back.  It gives this hidden potential DPS along with increased survivability. 

Now you guys have an insight to how to get the most out of your skill point.  It's simple, right?  It shouldn't be tough.  Let's put that knowledge to use then.  Here's a little homework for you guys:

Make the most effective and efficient skill build for Nerubian Weaver.  You must include rationale for taking such route.  You are allowed to include items to justify your reasoning.  There's usually no ultimate "one build".  But I'm sure you guys can come up with a build that can fit most games.  For you HoN players, do the same for Madman.