The following was originally posted a few years ago on http://advrider.com by my friend Chris Doyle who has kindly given me permission to re-post it here. While it may deal mostly with motorcycles, the information is applicable to following all Dakar racers.Follow him on twitter and his site.
Enjoy!
@RallyRaidReview http://www.rallyraidreview.com/
Dakar following 101...Timing and Scoring...
...or how to drink from the fire hose and enjoy the taste.

The important things to know up front are the basics or Dakar rule applications. There are two sets of rules, French and English and the two may or may not be the same depending on the section.

It's also important to know that this is the ASO and the ASO may or may not apply those rules in any sort of logical or consistent manner. The good part is that the inconsistency tends to even itself out as the rally grinds on from stage to stage. That is to say in most general cases, what is considered by the fans to be an unfair ruling against a rider on day 2 may be repaid in the form of a ruling against his main rival in a later stage.

In the end of the rally, things tend to even themselves out and no real preferential treatment is afforded to anyone, even the French.

The stage:
Liaison:
Each stage can be broken up into several pieces, 'Liaison', 'connection', 'road section', 'transit section' are all the same thing. They all refer to a section of the total stage that is not timed, but is basically how the riders get from the bivouac to the start of the timed section. Liaison distances can be anywhere from zero to several hundred kilometers and can be before, after, or at both ends of the timed stage.

Depending loosely on finish placings the day before, riders are assessed a start time. Riders starting 1 through 10 are sent off in two minute intervals, starters 11 through 20 in one minute intervals, 20 on back in 30" intervals. Every now and then they'll stage mass starts of 10 or 20 riders at a time, but is may only happen a stage or two each year if at all.

Timed section:
This is where you get your boogie on. If you are in the top 30, you are dropping the hammer for a good placement. If you are farther back, you are most likely looking to survive to ride the next stage. It's important to know the motivations for participating. For the top 5 or 6, they are in for a win, nothing less is acceptable. For the rest of the top 30, they are hoping for a good placement in order to attract sponsors to have a go next year, maybe to gain some exposure or get noticed by a factory or top team, or they simply want a good showing to kick off a career in rallying.

The rest of the field consists of riders for which the finish is the win they desire. Whether it be a dream fulfilled, an adventure undertaken, or simply someone with more dollars than sense, these riders will never battle with the likes of Despres or Coma, but they will battle even more fierce opponents like sand, dunes, time, darkness, and their own will and stamina to carry on.

There are a few anomolies to these unwritten rules. Riders like Simon Pavey, Annie Seel, Mick Extance, Tina Mieir, Silvia Ginnetti, and Kemal Merkit. Riders who come back year after year, hover in the 50's to 60's as far as time and placement and gradually move up towards the end more out of attrition than outright speed. They have flashes of brilliance now and then, but they know they will not win a stage or even end up on the podium. For them and riders like them, the motivation is intensely personal and seldom discussed.

Every now and then a timed stage will include a neutralisation. A neutralization is usually an untimed section in the middle of a timed stage where riders need to get from one area to another. Usually this is when there is no feasible racing route through a particularly long distance. If it's a short go like through a village in Africa, the ASO will impose and closely monitor a speed limit. If it's long, they'll simply throw in a neutralisation section.

What we end up with is two timed sections and the total time of the stage becomes an aggregate of the two sections. Think of it like two stages in a single day with the times added together.

The end of a timed section may be right at the bivouac or there may be another liaison from the end of the timed stage to the bivouac.

Timed sections are broken into many segments denoted by waypoints. As a rider approaches a waypoint, once they get within a defined perimeter, the GPS comes to life, and an arrow points the way to the waypoint. When the rider gets to within a closer set distance from the waypoint, it registers, his time is recorded and he or she takes off in search of the next waypoint (WP). Interspersed through the stage are also Checkpoints. These are spots where (as far as I know) time is manually recorded by an ASO official and the riders card is marked. CP's may or may not match up with a WP, but they usually do.

I won't get too deep into the rules about delays, late starters, etc... as all that exists in the rules pdf here, but suffice to say, the ASO has penalties for everything and as I said above, the assessment of those penalties may or may not make sense and may or may not show on the timing lists.

Stage map from the Dakar.com main page showing CP's.

Stage map from the live timing or iritrack from Dakar.com showing WP's.

From the same page, this is the stage profile of the WP's. I actually like this better than the stage map as it shows the km's. One note of caution, the ASO is seemingly intentionally vague on their km markings and whether they actually line up with WP's or just denote the end of a particular type of surface, ie. the transition from gravel to dunes, etc...

The iPhone App map is actually the best and more like the old Dakar.com it clearlt shows the CP's and a nice dashed line to the km marking. Notice for instance, CP4. Had the line not been there, it would look like CP4 lines up with km609 when in fact it is listed at km593 a full 14km's earlier. When expecting a rider to come in, 14km's in the dunes can be quite a lot of time.

Hope fully that explains the basic mechanics of the stage and the movement of riders from bivouac to bivouac each day.

Timing:
First of all, if you want to track times like the best of them, yuou have to know your lists inside and out. Don't underestimate the difficulty of trying to figure out time splits while the pressure builds about posting it first as to not repeat, or 205, already posted information. PackMule has this down pat and is faster than anyone. Sure the time sheets give the split times form the stage leader, but what if you want to see how much time 5th place Ze Helio gained on 3rd place Chaleco from waypoint 4 to waypoint 5? This is where list knowledge comes in.

Waypoint times show up in the live tracking "follow your favorites" section of the dakar.com site and checkpoint times show up in the live tracking for the day here.

As you learn to use both of these, you'll understand how they can compliment each other.

For 2011, the ASO has drastically revamped their site and really took the wind out of the timing sails. One crucial element now gone is the physical time of day that a rider posted a WP or a CP. This was immensely helpful in tracking riders that have been lost, broke down, crashed, or simply slowed down. Now we only get the physical time of day for the start of each rider.

The four most important things to remember are this:
1) ASO timing is notoriously spotty. Not the times themselves per se, but when and if they show up. Because a rider has not posted a WP time does not mean the worst. The iritrack may not be working, the ASO official may have gone for coffee, the rider may have missed the waypoint.

2) Always keep in mind the start intervals of the riders. Cyril Despres may be leading Marc Coma by 10" from WP to WP, but when Cyril posts his time at a WP and Marc's time doesn't show up 10" later, many people panic that Coma fell or slowed up, or whatever. Keep in mind that Coma may have started physically on the stage 10 minutes after Despres. Understand that Coma's time may not show up until the 10'10" have passed. Once you get that, you'll learn when to expect a rider through a WP or a CP. Packmule and Flood are the masters of this and can usually pinpoint to a few seconds when a rider's time should be.

The live WP to WP timing is usually referred to as the iritrack. The CP to CP timing is usually referred to as the Posis list after the French name for it. When you really get skilled, you can start venturing into the French version of dakar.com because for the most part, the times are updated a little faster there. I'm speaking out of class here and giving up secrets bourne out of years of mad following, comparing notes/posts, and even sometimes having our own little races as to who can mine the times and post the results first. Many times followers get stunned when Packmule posts that Coma bested Despres in the last section to pull the stage win when no one else can even see the final times displayed. Packmule's French site list skilz are strong.

3) Lastly and I suppose equally important is to know that the ASO seemingly gets lazier and lazier about updating times as the day goes on. The fast guys have their times refreshed up to the lists pretty quickly, but if you are following a guy who is languishing in 134th place and is still out on the stage 6 hours after the first guys are in, good luck on keeping track. A perfect example was Luis Belaustegui and Mike Stanfield from Stage 5. Neither one showed on the final finish times, but when I checked the start list for Stage 6 late the night of Stage 5, low and behold, there they were. What this means is that the ASO crew packed it up. The times will ultimately get recorded within the ASO, but they may never show on the list. If they are on the next days start list, they made it in.

4) Withdrawals and the withdrawal list. Every other list is secondary to the withdrawal list and subject to change. In my experience, one that never does is the withdrawal list. If your rider ends up there but it's still a mystery where they are, they are out. I have never seen a rider make the list but still somehow continue on. I am not sure why the ASO is so spot on with withdrawals and spotty on everything else, but that's how it is.

It probably is used as their catering list from bivouac to bivouac to prove to the catering crew how much food they should prepare

DSS, WP, CP, ASS, etc...
DSS - Starting point of the timed stage (French abbreviation of Departe Special Stage)
WP - Waypoint (electronically recorded time stamp)
CP - Checkpoint (manually recorded time stamp)
ASS - Not the nice Chilean girl screaming "Chaleco, Chaleco, Chaleco", but the finish of the timed stage. (French abbreviation for Arrive Special Stage)

As I mentioned, the various lists will give you just about all you need to track the riders. Don't be afraid to open up some tabs or some separate browser windows and have your various time lists up on each ready to toggle and refresh at a moments notice. The ASO's fancy new auto refresh will have you spitting nails by the fifth time you are copying a time from 14th place at WP5 and it refreshes back to the start times of the cars before you can select copy but it is what it is.

F5 - many are unsure of this and what it means. For us geeks that have been hovering over time sheets for the past few years, F5 became a joke about how often we are refreshing the browsers. For most PC based computers, the F5 key refreshes the browser just like the refresh icon does, but since many are typing it saves time to hit F5 over grabbing the mouse and clicking refresh. Nothing more complicated than that.