You've probably wondered what chance Jimmy Gibbs Jr. has to appear? We didn't think about that either, but while reversing Director we accidentally stumbled upon a function in the game code responsible for the appearance of Jimmy Gibbs Jr.

Let's take a look when and how Jimmy appears and on what days!

The first thing we will show as proof is the assembler instructions from the game code and the resulting pseudocode.

1. All starts with a call to the CDirectorScriptedEventManager::OnFinaleStarted function, its name speaks for itself. It contains several conditions for different situations, one of them includes whether the current map is the 4th chapter of Dead Center (c1m4_atrium).
   
   
   
   
2. If the current map is c1m4_atrium we move on to the next instruction which checks the constant defined at the compilation of the game (z_jimmy_time), this constant is zero, this means that a date (you'll see it a bit below) check will be carried out, otherwise Jimmy Gibbs will always spawn.
   
   
   
   
3. If the constant is zero then we move on to checking the date. If the current year is more than 2009 or the day of the year isn't less than 331 (November 28) then we convert the current date into days.
   Next, subtract the date (in days) November 28, 2009 from current date and check on the frequency.
   
   Check on the frequency: modulo division by 15, if the result is 0 (division without remainder) then Jimmy's spawn timer is activated. Thus, every 15 days starting November 28, 2009 you can see Jimmy Gibbs Jr.
   If all conditions are correct the game calls the ZombieManager::StartJimmyTimer function.
   
   

What it looks like as pseudocode:

1. The timer will have a time when Jimmy Gibbs can appear, it calculates a random value in the range from 60 seconds to 240 seconds (1 - 4 minutes). The resulting number will be added to the current time and written into the timer structure.
   
   

Pseudocode:



The SelectModelByPopulation function is called when engine wants to spawn Common Infected depending on the current population.
This suggests that once Jimmy's timer expires, Jimmy won't appear immediately until engine wants to spawn some CI.

1. At the beginning of the function base mode of the current game will be checked, if it's Coop the game will try to spawn Jimmy.
   
   
   
   
2. At this step the conditions for the appearance of Jimmy Gibbs are re-checked. If nothing has changed, proceed to checking the timer timestamp.
   
   
   
   
3. Сheck that the timer has never been started yet. If the timer time is greater than zero and less than either the current time then again we try to determine (if it failed before) whether we are on c1m4_atrium. If everything went well move on to the end instructions.
   
   
   
   
4. If the constant z_jimmy_time is 1 then the model to spawn Jimmy Gibbs will be immediately returned. Otherwise, will be generated and compared a random number between 0.0 and 100.0. If the random number is less than 33.0 then Jimmy's model will be returned, otherwise another infected (that is the chance was missed).
   
   

Pseudocode:

• The game starts the timer for Jimmy Gibbs' spawn after start of the final event on the 4th chapter of Dead Center.
  
  
• The timer starts in a range of 1 to 4 minutes.
  
  
• Jimmy Gibbs appears every 15 days depending on your computer's system time.
  
  
• When Jimmy Gibbs' spawn timer has expired he will spawn with 33% chance.
  
  
• You can see Jimmy Gibbs if the year in your computer's system time is more than 2009 or the day of current year is at least 331 (November 28).
  
  
• Jimmy appears if you're playing in Coop mode (no Realism/Versus/Scavenge/Survival).

Jimmy shows up every 15 days: 1 / 15 = 0.0666666666 (0.066.. * 100% = 6.6%)

Spawn chance 33%: in fractions it will be 33% / 100% = 0.33

Both events are related, so we multiply them: 0.0666666666 * 0.33 = 0.022 (0.022 * 100% = 2.2%)

Chance - 2.2%

Dates when we can see Jimmy Gibbs Jr. in this year:

• 12 January, 2022
  
• 27 January, 2022
  
• 11 February, 2022
  
• 26 February, 2022
  
• 13 March, 2022
  
• 28 March, 2022
  
• 12 April, 2022
  
• 27 April, 2022
  
• 12 May, 2022
  
• 27 May, 2022
  
• 11 June, 2022
  
• 26 Jun, 2022
  
• 11 July, 2022
  
• 26 July, 2022
  
• 10 August, 2022
  
• 25 August 2022
  
• 9 September, 2022
  
• 24 September, 2022
  
• 9 October 2022
  
• 24 October, 2022
  
• 8 November, 2022
  
• 23 November, 2022
  
• 8 December, 2022
  
• 23 December, 2022

I wrote a script as add-on that shows all the dates of the current year, the nearest day and the ability to check any year when Jimmy Gibbs will appear. Be sure to create a local server, then use chat commands described in the add-on.

Click me

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